Gunsmithing

GUNSMITHING THE COLT DOUBLE ACTION REVOLVERS

The purpose of this section is to make the Colt owner aware of the pitfalls of opening up his Colt and attempting to do his own repairs, and to offer advise on what repairs to undertake and what to leave to genuine Colt qualified experts.
Make no mistake, the old style Colt action revolvers are complex mechanisms from another century.  Virtually every internal part was hand fitted at the factory by Master assemblers with years of training and experience.
Unlike automatic pistols, almost no revolver parts can be simply dropped in.  Parts like the barrel and cylinder require extensive fitting and adjusting using very expensive tools and gauges. 
The situation gets worse when action parts are installed due to the complex design which is nothing at all like other brands of revolvers.

Mechanically, the Colt double action revolvers are broken into the old style actions and the new style actions.
The old style action was used on revolvers like the Detective Special, Cobra, Diamondback; and Python; and the newer type Colt double action used on revolvers like the Mark III, Mark V, King Cobra, Anaconda, and Magnum Carry.
While the new style action models are much simpler designs, even then there are special considerations that make repairs a tough job with some unexpected surprises lurking for the untrained.
The old style actions are complex, intricate designs dating back to the 1890's.  All old style Colt firearms were hand fitted and made from over-sized forged steel parts right up into the 2000's.

The old Colt action required careful hand fitting by Master assemblers.  The action parts were made of over-sized forged steel parts that were built by hand filing, stoning, and even bending parts to achieve proper fit and operation.
In the old style revolvers, right up to the last Pythons made in the early 2000's few parts would drop in.  Virtually every part was an individually hand fitted part.
The old style Colt action is often called "a watchmakers gun" due to this complex design with tiny critical working surfaces.
Each part in the action performs at least two or more functions and these functions are seldom related to any other function.
The old action design is very counterintuitive.  When observing the function of the action, what appears to be happening is not what's happening at all.
In the old days when Colt's were very popular with law enforcement and civilian gun owners, most good gunsmiths had to fully understand the action and know exactly how to work on it.

However, as the old Colt designs began to be discontinued and the old gunsmiths began to retire or die, new gunsmiths never learned the ins and outs of it.
New gunsmiths are fully conversant with the S&W, Ruger, Dan Wesson, and Taurus action, but know nothing of how the old style Colt's work, or know the special techniques needed to work on them.
This can cause serious problems with getting an older type Colt repaired.
It's not uncommon for a gunsmith who's fully qualified to work on other revolvers and who understands how they operate, to get himself in trouble with an old Colt action.
Being an expert with S&W or Ruger, the gunsmith may think that the Colt is nothing more than just another design and that he can figure it out just like he did with the other brands.
By the time he realizes that, in fact, the Colt is NOT anything like the other brands, he's in over his head.
Without a firm understanding of how all this odd stuff works the original problem isn't repaired, and other damage is done by blind attempts to alter parts hoping to hit on a fix that will somehow magically get everything working right.

The problem with the old Colt action is that if you alter something HERE, unexpected things happen over THERE.
The new style action revolvers while simpler designs with fewer parts also have some unique problems with repairs.
The new revolvers were built using parts made of "sintered steel".  This is a process in which internal parts are made by injecting powdered steel into a mold and heating it until the metal melts and fills the mold.  When the mold is opened a virtually finished part is removed, requiring only surface hardening and finishing.
This is an earlier version of today's MIM (Metal Injection Molding) in which the metal is mixed with a polymer and injected into a mold.  When the mold is heated the polymer dissipates, the metal melts and fills the mold, then shrinks a known amount.  Again, when the mold is opened an almost finished part is removed and surface hardened.

In these later Colt's repairs are done, not by refitting parts as in the old action, but by simply replacing worn or damaged parts with new parts.
The problem with repairing these revolvers, is a strong tendency to decide to alter a part so that it will work instead of replacing it as intended.
When the factory repairs one of these designs, the gunsmith pulls a part from a bin full of parts and test fits it.  If it doesn't fit correctly, he selects another part until a part does fit correctly.
The problem for a local gunsmith or gun owner is that he doesn't have a bin full of parts to pick from.  He has to order ONE part from a parts house and hope it fits.  When it doesn't he's left with the prospect of sending it back and ordering another part, which means paying more postage.
The inclination to just alter the part to make it fit is difficult to resist.
Altering the part is where the danger is.
Since these sintered metal parts have an extremely thin "crust" of almost glass-hard metal, any stoning or polishing will break through the thin coat and expose the soft inner metal.
The exposed soft metal will wear quickly and will often cause unsafe conditions as the part wears.
Many local gunsmiths are not aware of this danger and will routinely stone or polish these parts attempting to repair the gun.  The wear may not manifest itself for some time, by which point the gunsmith will not take responsibility for his mistake.

The next hazard for getting local repairs is that few gunsmiths have the specialized tools and gauges needed to work on the Colt revolvers.
As example, to correct a condition known as "cylinder end shake", a special hydraulic tool is needed to stretch the collar on the cylinder.
It's likely that only Colt and possibly one or two other repair services ever had such devices.  Without the device, cylinder end shake on most Colt's cannot be corrected.  This may lead a local gunsmith to attempt some other incorrect repair method that can ruin a cylinder.
Many local gunsmiths are not experienced revolver experts.  Many have no idea of the correct method of removing and installing a revolver barrel, and few have the special tooling for Colt's. 
This unfortunately leads to revolver frames destroyed by someone shoving a hammer handle through the frame and twisting the frame off the barrel instead of using the special revolver frame wrench and polymer frame inserts.

Gunsmithing the Colt double action revolvers requires a significant investment in tools and other materials and time spent learning how to use them. 
Unfortunately, few of today's gunsmiths have either the tools or the knowledge to work on Colt revolvers.
Taking the word of a gunsmith that he really does (honest) understand the Colt's and that he really does (honest) have the specialized tools needed to work on them can lead to disaster that can be avoided.
For this reason, a smart Colt owner will only trust repair services that are KNOWN to be true experts.
Currently the known competent Colt repair facilities are:

Colt Firearms. 
No one knows more about it then Colt.  They are no longer doing any kind of work on some older models for which they no longer have parts.
Their prices are competitive and turnaround is usually faster than anyone else.
http://www.coltsmfg.com/

Cylinder & Slide Shop.
Cylinder & Slide are a true world class custom shop.  They offer repairs and custom work on most Colt revolvers, including most of the older guns.
Prices are high, and turnaround is slow, but the quality of work approaches the Colt factory.
http://www.cylinder-slide.com/

Frank Glenn.
Glenn is well known for his expertise with the older Colt actions, and offers super action/trigger work on guns like the Python.
Prices are very good and turnaround seems to be fast.
http://www.glenncustom.com/

If and when we become aware of other proven Colt gunsmiths, we'll add them here.
While there are no doubt other competent Colt qualified gunsmiths, until we become aware of them and can verify the quality of their work we won't recommend them.

DOING YOUR OWN COLT GUNSMITHING
Attempting to gunsmith a Colt revolver without having the special tools or the knowledge and experience needed, very often leads to a defective gun.
A good many of the guns for sale on the internet gun auctions, in gun shops, and at gun shows have defects caused by untrained attempts to gunsmith the gun.  Often the owner wants to "improve" the trigger action or repair a minor problem and winds up doing damage to the gun.
With the gun no longer working properly or actually damaged and facing the expense of a trip back to the factory for proper repairs, the gun often winds up for sale.  Very seldom does the seller inform the buyer that there's a problem, or the seller may not know that a gun he bought and is selling is defective. 

TOOLS AND REFERENCE MATERIALS.
There are several tools a Colt gun owner should have, whether he wants to work on his Colt or not:
A key "tool" is to get a Brownell's catalog.  This is THE gunsmith's supply source for tools and equipment.  Brownell's will refund the price on the first order, and will send a catalog on request with any order.  This is the best "gun stuff" catalog in the world.  Everything Brownell's sells is excellent quality and they have a no questions asked return policy.
http://www.brownells.com/default.aspx

SCREWDRIVERS
Never use standard screwdrivers.  These will damage gun screws and the areas around them.  Gunsmith screwdrivers are designed to have parallel tips both on the front and sides.  Standard drivers are tapered on both front and sides.  These will slip upward out of the slot damaging the top of the slot.  The tapered sides will scar up the edges of recessed screws.
Nothing looks worse than a fine gun with chewed-up screw heads from using non-gunsmith screwdrivers, and nothing says "gun butcher" more clearly.
Since screws may vibrate loose under normal use, a good Colt-specific screwdriver set is a good investment.
By far the best gunsmith screwdrivers are the Brownell's Magna-Tip driver bits.
These are extremely hard, very smooth, high quality bits.  Brownell's offer more sizes of bits than anyone, and if a bit is damaged simply emailing Brownell's will have them send you a new bit FREE.
Brownell's sell Magna-Tip Master sets in various sizes, but you can just buy the necessary bits to work on Colt double action revolvers.
The recommended handle for general pistol work is the Brownell's Law Enforcement size handle which is the perfect size to offer good control.
http://www.brownells.com/.aspx/pid=412/ttver=2/Product/LAW_ENFORCEMENT_HANDLES

The recommended Magna-Tip bits for Colt DA revolvers are:
.150-2
.150-3
.180-2
.180-3
.210-3
.210-4.
The reason for the extra thicknesses is to take into account minor variations in the thickness of screw slots.
http://www.brownells.com/.aspx/pid=41568/ttver=2/Product/MAGNA_TIP_SUPER_SET_BITS

The Jerry Kuhnhausen book "The Colt Double Action Revolver: A Shop Manual, Volume One" for the older style action guns, or "The Colt Double Action Revolver: A Shop Manual, Volume Two" for the newer models.
These books can be bought from Brownell's, Midway USA, or direct from the publisher, Heritage Gun Books. 
These books were written for use as training aids for new gunsmiths and cover every possible aspect of disassembly, inspection, reassembly, and gunsmithing of the Colt revolvers to factory standards. 
The methods shown are those used by the Colt factory to restore a Colt revolver to factory specification condition.
For any but the most simple Colt gunsmithing tasks, we strongly recommend you buy the Kuhnhausen book appropriate for your model of revolver.
All the tasks described in this section are fully described and pictured in the manuals.
http://www.brownells.com/.aspx/cid=0/k=shop+manual/t=P/ksubmit=y/Products/All/search=shop_manual
http://www.gunbooks.com/

If you decide you want to attempt a simple repair to a Colt revolver, there are several tools you'll need.  This is by no means a complete list of Colt tools and gauges, this is only intended for simple disassembly.
A magnifier visor.
A good bench light.
A 3/32" pin punch.

NOTE:  If used incorrectly the above tools including the screwdrivers and punch will most likely leave you with a damaged finish and damaged screw heads but a still-functioning gun. 
However incorrect use of the next two items can leave you with a non-functioning or improperly functioning firearm.  Please be certain you know what you are doing before attempting to use these items.  If you are familiar with working on a cylinder and ejector rod then these are a necessity.  If not think twice.
A Colt ejector rod crane bushing tool from Brownell's.
http://www.brownells.com/.aspx/pid=712/ttver=2/Product/COLT_CRANE_BUSHING_TOOL
An ejector wrench for the older style ejector assembly as used prior to 1973:
http://www.brownells.com/.aspx/pid=605/ttver=2/Product/COLT_WRENCH

PARTS
When parts are needed for repairs, you immediately run into problems.
For many of the later models of revolvers the only company that has any parts at all is Colt Firearms and even Colt is running out of critical parts. 
Colt will not sell most revolver parts since they are retaining what's available for use in their own repairs.  If a later model needs a part, the only choice may be to send the gun to Colt for them to supply and install it.
For the older style action models, the supply of parts is more widely available, but most of those parts are used parts.
Most of the parts houses now have mostly used parts that have already been fitted to a revolver.  Since the old style Colt action requires that parts be altered to fit a specific frame, the fitted critical surfaces may be too small to fit your revolver and the part is useless.
With the supply of critical action parts, barrels, and cylinders drying up, the situation for a continuing supply of usable parts is not good.
Parts will be available, but it may be necessary to use more difficult techniques to allow them to fit a specific revolver.
This level of work is best left to a genuine expert.
Jack First Parts is now beginning to manufacture some new parts for the older models.  Among the parts they make are cylinder locking bolts for the "E&I" frame models and hands.
However, these parts are more on the order of rough semi-finished, oversized raw parts then genuine Colt parts and will require extensive shaping before they can be installed and fitted.
Again, this is something best left to an expert.

PARTS HOUSES
In all cases, parts may be available but not listed on a web site.  To lower chances of getting the incorrect part, whenever possible call or email to insure you and the parts house are on the same page.
Be aware that if you alter a part in any way, the parts house will not take it back or exchange it.  Since almost all of the old style models require that parts be altered to fit, be certain it can be used in your gun before you start altering the part to fit.  Once you've started working on a part, the parts house will not take it back.
The new style models parts are intended to be dropped in with no fitting.  If you get a part that won't fit, most parts houses will exchange it for another.  Altering these later models parts ruins them.
Be very aware that there are dozens of models of Colt pistols, many using the same parts for multiple models, others using parts unique to a single model.  Guns made prior to World War Two may be the exact same design, but minor manufacturing changes in the parts may prevent them from being used in post-war guns and vise versa.
Thread sizes on ejector rod heads and bolt screws changed, among other differences.
Parts houses often can't keep up with what part will fit what model, so it's up to you to learn the in's and out's of the various models and what parts will interchange.
It's not unusual for parts houses to send the wrong part.  With dozens of models and thousands of parts in bins, it's easy for even a good parts house to simply pull the wrong part.
Last, always remember that the older style Colt's parts were all made over-sized and were stoned, filed, and bent to fit a specific gun.
Almost all parts available these days are used parts that were fitted to a different gun.  A used part may not be usable at all in your gun if critical areas are now too small to allow fitting.
In these cases, your only option is to return the part and hope the next one can be used.
Brownell's.  Revolver parts are very limited but are factory new, not used.
http://www.brownells.com/.aspx/mid=99/schematics/Colt_

Gun Parts Corporation.  Mostly used, but some new.
http://www.gunpartscorp.com/catalog/Models.aspx?catid=167

ColtParts.com.  Mostly used.
http://www.coltparts.com/index.html

Jack First.  Manufacturing some new Colt parts, and carry genuine new and used Colt parts.  One of the best parts houses, you have to call.
http://www.jackfirstgun.com/

Poppert's.
http://www.poppertsgunparts.com/index.htm

Wisner's.
http://www.wisnersinc.com/

Hoosier Gun Works.
http://www.hoosiergunworks.com/

Bear Creek.  Click on Colt and wait.
http://www.parts4guns.com/

Bob's Gun Parts
http://www.gun-parts.com/index.html/

Schludershot. All used.
http://www.schludershots.com/

Nu-Line Guns.  Possibly some Colt parts. 
http://www.nulineguns.com/index.php

CHECKING THE TIMING OF THE OLD STYLE COLT REVOLVER
Revolver "timing" is simply the process of the unlocking, advancing the cylinder to the next chamber, and re-locking it.
This must happen in the proper sequence and at the proper moment.
In most revolvers this process is far less critical than the old style Colt revolver action.
In the old style Colt's, correct timing is absolutely critical and timing must be exact.
These instructions cover all the older model Colt's like the Detective Special, Cobra, Diamondback, Official Police, Officer's Models, original Trooper, and Python.

BOLT RETRACTION AND "SNAP BACK".
Open the cylinder and look at the small "lug" in the bottom of the cylinder window. This is the cylinder locking bolt.
Cock the hammer, and watch as the bolt retracts into the frame and pops back out.
The bolt MUST begin to retract THE INSTANT the hammer begins to move.
There MUST be NO (ZERO) hammer movement possible before the bolt starts to retract.
The bolt should retract smoothly with no hesitation until it's fully retracted, then it must pop back out with a clean "snap".
There should be no hesitation, and no amount of "creeping" back out.

CYLINDER UNLOCKING.
Close the cylinder.
Use your left thumb or fore finger to again cock the hammer, closely watching the cylinder bolt as you SLOWLY cock the hammer.
As the hammer comes back, the bolt will retract away from the cylinder.
The bolt must retract far enough to unlock the cylinder BEFORE the cylinder begins to rotate.
If the bolt is still slightly engaged with the cylinder lock notch, the cylinder will be attempting to turn while still partially locked.
This produces a "catch" or "hard spot" in the trigger pull and will damage both the bolt and the cylinder lock notches.
This often appears as metal "pulled out" of the lock notches, with rounded off and burred notches.

BOLT DROP TIMING.
Continue to cock the hammer, LIGHTLY laying your right index finger on the cylinder just enough to prevent "free wheeling".
Watch for the bolt to drop back onto the cylinder. WHERE the bolt drops is CRITICAL.
The bolt MUST drop onto the leade or ramp in front of the actual cylinder notch.
If the bolt drops too soon, (in front of the notch ramp), it will mar the finish of the cylinder.
The bolt should drop into “about” the middle of the ramp.
If the bolt drops late, (farther toward the actual locking notch) the revolver may display "cylinder throw-by".
In this condition, during double action shooting the cylinder may rotate PAST the locking notch, and fire in an unlocked condition.
It's the nature of the Colt action, that a hesitant or jerky trigger pull by the user can induce throw-by in even a properly tuned Colt.
The Colt trigger should be pulled with a smooth, even pull, with no sudden jerks at the beginning.

CYLINDER BOLT LOCKING.
Continue to pull the hammer back and both watch and listen for the bolt to drop into the cylinder lock notch.
The bolt must drop into the actual lock notch before or just as the hammer reaches full cock.
The most common Colt mis-time situation is the hammer cocks before the bolt drops into the lock notch. (Hammer is cocked, but cylinder isn't locked).
In this condition, with the hammer fully cocked, you can push the cylinder slightly, and you will hear the "CLICK" as the bolt drops into lock.
In my experience, most Colt's leave the factory with the bolt dropping a little late into the leade, but usually wear in to correct timing.
If the bolt drops onto the cylinder early, no real problem, but there will be extra finish wear.
If the bolt drops late (closer to the lock notch) the cylinder may "throw by" or rotate TOO far in double action and this can cause off-center primer hits and firing while unlocked.

CYLINDER LOCK UP.
The older style Colt's had what was known as the Colt "Bank Vault" lock up.
When the trigger is pulled and held back there should be no rotational movement of the cylinder.   In these Colt's the hand forces the cylinder chamber into into perfect alignment with the bore and locks it tightly there.

Each of these checks should be done on EACH chamber. All of these checks are better done individually. In other words, do the bolt retraction check on all six chambers, then do the bolt drop test, and so on.

A properly timed old style Colt will:
Have a smoothly functioning bolt with no sticky or hesitant movement.

There will be zero movement of the hammer without the bolt starting to retract.

Unlock before the cylinder begins to turn.

The bolt will drop onto the middle of the ramp.

The bolt will drop into the lock notch just before or as the hammer reaches full cock.

Have a smooth trigger pull, which does "stack" or get heavier as the trigger is pulled.

CHECKING THE TIMING OF THE NEW STYLE COLT REVOLVER
Here's how to check timing on the Mark III and later Colt action:
This covers post-1969 Colt DA revolvers, to include:
The Trooper Mark III, Lawman, Metropolitan Police, Official Police Mark III, Trooper Mark V, Lawman Mark V, Peacekeeper, and King Cobra. 
This "probably" covers the Anaconda and the new small frame revolvers based on the "SF" frame, like the SF-VI, the DS-II, and the Magnum Carry since these are all based on the King Cobra.

BOLT RETRACTION AND DROP.
In these guns, the bolt retraction and drop is judged by TRIGGER movement.
The bolt should begin to retract within 1/6 to 1/4 of the triggers total movement and drop after about 2/3 of it's total arc.
This is NOT 1/6 to 1/4 INCHES, it's total trigger movement.
What counts is that the functions occur correctly even if trigger movement is slightly off.

BOLT ACTION.
Open the cylinder and look at the small "lug" in the lower frame window.
This is the cylinder locking bolt.
Slowly cock the hammer and watch the bolt as it retracts.
When the bolt begins to retract, it should move smoothly in, then pop back out with a clean "SNAP".
There should be little or no mushy or hesitant movement.

BOLT DROP.
Close the cylinder and slowly cock the hammer.
Watch the TRIGGER AND the BOLT.
The trigger should move between 1/6 and 1/4 of its arc before the bolt begins to retract.
What's critical here is that the bolt MUST be retracted enough to be completely free of the cylinder locking notch BEFORE the cylinder begins to rotate.

BOLT DROP.
Again, the standard for bolt drop is based on TRIGGER movement.
The Bolt should drop after about 2/3 of the trigger's total travel.
What's critical here is, the bolt should remain retracted away from the cylinder while the cylinder rotates and then drop back onto the cylinder before the trigger gets too close to the end of it's movement, the sooner the better.

CYLINDER LOCKING.
Before the hammer is cocked, the bolt MUST drop into the cylinder locking notch, locking the cylinder.
Unlike the older Colt actions, there's a wide range of adjustment allowed, and the bolt DOES NOT drop into the leade to the cylinder locking notch.
Since the bolt is designed to ride the cylinder for most of it's rotation, these Colt's will have finish wear almost all the way around the cylinder like S&W's do.
The design of the hand in these revolvers is also more S&W-like, in that LENGTH is not a factor, WIDTH is the critical dimension.
For this reason, these revolvers seldom develop "hammer's cocked, but cylinder isn't locked" problems.
The old Colt's were checked for tight lock up by pulling the trigger and holding it back to check for a solid cylinder lock up. 
These newer revolvers are not checked with this method since the cylinder MUST be slightly loose with the hammer cocked to allow the bullet passing from the chamber to the bore to force the chamber into alignment with the bore.
Some cylinders may feel tightly locked but enough backlash is built into the action to allow it to move when fired.

Unlike the older Colt's, these guns are designed to have parts replaced, and CANNOT be re-fitted or re-tuned. If they have a problem, new parts are installed.
Also unlike the old Colt's, parts cannot be altered or even polished much. The parts are sintered steel with a thin, glass hard coating.
Any attempt to polish, heat and bend, or alter parts will break through the coating, destroying the part.
As you can see, the timing is much less critical here, and you live with what ya got.
Tuning for a better trigger is limited to installing spring kits, and NO re-fitting of worn parts.
To make up for all this, you get what Master Gunsmith Jerry Kuhnhausen believed was the strongest mid-frame revolver ever built.
 
So, the bolt should retract before the cylinder begins to rotate.

The bolt should drop back onto the cylinder before the trigger gets too close to the end of it's movement, the sooner the better.

The bolt should lock the cylinder before the hammer gets even close to cocked in single action or before the hammer drops in double action.

If there's a problem of any kind, the action CANNOT be re-fitted or repaired by normal methods.

If there is a problem, the ONLY "fix" is parts replacement.

These actions are assembled and repaired by selecting a part from a bin, and test fitting it.
If it doesn't fit, another part is selected.
This makes it tough for local gunsmith's who don't HAVE a bin full of parts and can lead to him stoning parts to make them fit.  This ruins the part which may not become apparent until the part wears.
For this reason, if you have a problem, send the gun in to Colt for a proper repair.

SIMPLE COLT GUNSMITHING TASKS.
REMOVAL OF THE CYLINDER FOR CLEANING
While it's not a good idea to remove a revolver's cylinder too often due to the risks of damaged screw heads, scratched frames and stripped or cross-threaded screws, it may be necessary to clean a cylinder assembly that's gummed up with old lubricant.
There are two types of Colt double action cylinder retention systems.
The pre-1950's system is a stud that interlocks with a screw in a figure-8 configuration on the right side of the receiver.
The stud retains the cylinder crane assembly and the screw locks it in place. 
When the screw is loosened a "skirt" or flange on the screw which interlocks with the stud retracts the stud up out of the frame allowing the cylinder and crane assembly to be removed.
Usually, it's not necessary to completely remove the screw and stud assembly.

To actually remove the old style cylinder assembly, carefully loosen the screw to retract the stud.
If the screw seems resistant, soak the area around the screw and stud with a penetrating fluid like Kroil and allow it to soak overnight.
If the assembly is still resistant there's a high risk of stripping the screw or breaking the thin flange on the screw making removal impossible without major gunsmithing work.  In this case, it's better to have a competent gunsmith remove it rather than damaging it and having to have the parts extracted.
Once the screw and stud are retracted enough to allow removal of the cylinder assembly, open the cylinder and rotate the cylinder until a flute lines up with the lower front of the frame.
Slide the entire cylinder and crane assembly forward and out of the frame.
If the assembly doesn't want to move forward, unscrew the retention screw a little more, or put some Kroil into the area where the crane enters the frame.  This will loosen any dried lubricant.

Once the cylinder assembly is out, you can clean the assembly.
One method for a badly gummed up assembly is to use small pieces of plastic or wood to hold the ejector up out of it's seat in the rear of the cylinder, and to hold the crane assembly forward from the cylinder.  Soak the entire assembly with a solvent like bore solvent or paint thinner to dissolve old lubricant and powder fouling.
After soaking for a few hours, "pump" the ejector rod and pull the crane in and out of the cylinder.
After the assembly is clean, flush with a solvent like alcohol or paint thinner and shake or blow out the excess.  You can also help dry by warming the assembly with a hair dryer.
DO NOT use excessive heat as with a torch or heat gun or by baking in an oven.  This can ruin the assembly.  All that's needed is to warm the parts.
Once the assembly is clean and fully dry, lubricate with your favorite lubricant, making sure to get lubricant inside the crane barrel and the cylinder where the crane enters.

The post-1940's cylinder retention is much simpler.
On the right side of the frame is what appears to be a large screw.
This is actually a hollow cap.
Unscrew the cap screw and lift it out.  Under the cap is a small spring and hollow plunger.  Remove them.
Then the cylinder can be opened, rotated so a flute lines up with the lower left of the frame and slid forward and out.

FURTHER CYLINDER DISASSEMBLY
Further disassembly of Colt cylinders IS NOT RECOMMENDED.
Further disassembly is needed only for replacement of parts and the risk of damaging the assembly is too high unless absolutely necessary.

OLD STYLE CYLINDERS
The old style assembly especially is a high risk situation.  Full disassembly requires two special tools. 
Extreme care must be taken not to damage the ejector.
Like all critical Colt parts the ejector is a hand fitted part.  You cannot simply buy a used ejector and expect it to fit the gun.  New ejectors are no longer available.
At the factory the ejector is precision ground on the end of the ratchet to set head space, and the ratchet lugs often need fitting to adjust both timing and barrel-chamber alignment on all chambers.
This requires an experts skills to fit and the correct machine tools.

To begin disassembly, the ejector rod head is removed.  Three EMPTY cartridge cases are put in the chamber to support the ejector.
The rod head is clamped in a padded vise and the cylinder is rotated COUNTERCLOCK-WISE to unscrew the rod head.
Next the ejector must be unscrewed from the ejector rod.
This requires a special wrench that fits down over the ejector ratchet area.
Removal and reassembly of the ejector is an especially risky task.  The ejector rod and ejector are staked together to prevent unscrewing.
This often causes distortion of the top threads on the ejector rod and can cause stripping of the threads.
During assembly the distorted threads make cross-threading or getting the ejector started straight a high risk and can easily cause the ejector to not screw on straight.  Once either happens major gunsmithing is needed to correct the problem.
If the ejector is damaged, only the Colt factor can supply and fit a new ejector, IF they have one to fit.

To remove the ejector from the crane requires a special Colt ejector rod crane bushing to unscrew the bushing which retains both the ejector rod and the ejector spring inside the crane.  The assembly cannot be disassembled without this tool.
The tool slips over the ejector rod and the lugs fit the notches on the crane bushing to unscrew it.
If the bushing is resistant, soaking with Kroil may help in removal.

NEW STYLE CYLINDERS.
The new, post-1973 type is a simpler, easier to disassemble unit, but there's still a risk of damaging it.  Again, unless there's no choice, don't disassemble.
To disassemble, put three EMPTY cases in the chamber to support the ejector.
Grip the ejector rod head in a padded vise and unscrew the entire rod by rotating the cylinder COUNTERCLOCK-WISE.
With the rod out, the cylinder comes off the crane and the ejector and the ejector spring will come out easily.
To reassemble, reverse the process.
Use caution when tightening the ejector rod.  You need the rod tight enough that it won't vibrate lose, but not so tight you risk stripping the threads of the rod or ejector.
If the rod tends to loosen, put a small drop of finger nail polish on the rod threads before tightening in place. 

REFITTING GRIPS
When replacing Colt factory grips you might find that factory grips may not fit properly, or may not fit in place at all.
This is usually due to variations in the location of the holes in the bottom of the grips that fit over the grip locating pin on the bottom of the frame.
A fast method of getting ill fitting grips to fit properly is to open up the holes in the grips slightly then use 5 minute epoxy to refit.
Apply a coat of wax to the grip frame to prevent the epoxy from sticking to the metal. 
Good waxes to use are Johnson's Paste Wax, available at most hardware stores and many Walmart stores, or shoe polish wax.  Do NOT use auto wax.
Apply a generous coat of the wax over the entire lower grip area, and don't wipe it off.
Use a small drill bit held in your hand NOT in an electric drill to open the holes in the grips to a slightly larger size.
Mix some hardware store 5 minute epoxy and pack a small amount into the holes.
Quickly install the grips and position them properly so they match the frame and each other properly.
Snug down the grip screw and allow to cure until the epoxy is getting to a firm rubber consistency.
Remove the grips and clean up any excess epoxy and wipe off the wax. 
Reinstall the grips and allow to fully cure.

COLT SIGHT WORK
Over the years from 1953 to 2003 Colt used several types of front sights and three types of rear sights on double action revolvers.
The early 1950's Colt rear sight was the early Accro sight with a flat sight leaf.
In the late 50's, the Accro was redesigned to include a "humped" rear area of the sight leaf to allow more elevation adjustment and a redesigned elevation screw assembly.
The third type of rear sight was the custom order Colt Ellison Target rear sight. 
Available as a special order, the Ellison was installed along with the Colt Patridge under-cut Target front sight.

EARLY COLT ACCRO REAR SIGHT
The first Accro rear sights were a different design than the later model.
The very early first year or two version had the front end of the sight leaf in a rounded shape.
Within a year or so, this was changed to a squared off shape to simplify production.

 

LATER EARLY ACCRO WITH SQUARE SIGHT LEAF

 

EARLY ACCRO DISASSEMBLED

 

LATER PRODUCTION ACCRO REAR SIGHT
This is the later type with the square notched base and the "humped" section to allow more Elevation adjustment.
Note the squared off front end of the leaf compared to the earlier type with rounded leaf and the squared blade notch.
Early versions of this type of Accro sight had a rounded "half moon" cut below the sight blade.  Late production changed to the square cut notch.
The elevation screw assembly was different then the early Accro versions.

 

ACCRO REAR SIGHT BLADE WITH WHITE OUTLINE.
Note the rounded lobe on the lower left and the sharp lobe on the lower right.
These need to be installed with the sharp lobe facing the windage screw.
Plain black sights are easy to get in the wrong way.
 

ACCRO SIGHT DISASSEMBLED
This is the mid production sight with the rounded blade notch in the sight base.
The elevation screw is a different design then the early version.
Note the two tiny balls and spring. These get lost easily.
Note: There's a pin that crosses through the sight leaf that retains the elevation screw.  This schematic doesn't show it.

 

COLT ELLISON TARGET REAR SIGHT
This was used on the Gold Cup Nation Match Automatic and as an option on the Python and other models.
The flat, grooved rear face gave a better sight picture, and gave more elevation adjustment.
These were fitted to the Python along with the Patridge Target front sight.

 

COLT STANDARD RAMP FRONT SIGHT
The Python used two pins to retain the sight until the barrel threads were changed in the 1990's. 
At that point only one pin was used to identify the new style threaded barrels.
The same sight was used with one pin on the 6 inch Diamondback.
In the late 70's or early 80's red or red-orange inserts were made standard for the Python.

 

COLT PATRIDGE TARGET FRONT SIGHT.
These were installed along with the Ellison Target rear sight on the Python
This type of Target sight was invented by famed early target shooter E.E. Patridge in 1892.

 

Colt front sights were separate pinned-in blades on the Python, six inch Diamondback, Trooper Mark III, Trooper Mark V, King Cobra, and Anaconda.
The Python and six inch Diamondback used the same blade, except the Diamondback had only one pin and the Python had two.
Later Pythons had new style barrel threads and the sight was changed to the same single pin blade as the Diamondback to identify the new style threaded barrels.
The other Colt's like the Mark III and later models used a different sight design. These do not interchange with the Python sight.
The Anaconda used a Python front sight.

Colt sights were available with plain black sights, on later guns colored inserts became standard.  Sight inserts ranged in color from cherry red to an orange-red.
A common question these days is "Where can I get a new sight for my Colt"?
The unfortunate answer is "Let us know if you find a source".
With Colt no longer selling sights, the parts houses are sold out, and the companies that made replacement sights stopped producing them, finding a Colt sight is a matter of blind luck.
Companies like Millet used to make Colt front sights with different types of inserts, but they've apparently stopped production.
At the current time, the only source of Colt front sights is Kensight who make a copy of the plain black Python front sight and the Target Patridge front sight.
http://stores.kensight.com/StoreFront.bok

There is no known source of the later Colt front sight as used on the Mark III through King Cobra.
The situation for Colt rear sights is not much better.  Some parts for the later type Accro are still available from the parts houses, but about the only source for complete rear sights is Ebay and the Internet gun auction sites.
Kensight does offer an exact copy of the late Accro and the Ellison rear sights. 
There used to be three types of Accro rear sight blades available, plain black, white outline, and with two white dots.
These days, rear sight blades are usually only available in plain black even on the rare occasion that one can be found at all.
At one time, Ruger rear sight blades were interchangeable with the Colt Accro blade, but whether this is still the case is not certain.

FRONT SIGHT COLORED INSERTS
You may desire to install a colored front sight insert to improve the sight, or an existing insert may be loose or have come out.
Installing or replacing an insert is a reasonably easy job using materials available locally.
You can also buy insert material or kits from Brownell's.
These are available as sheets of colored plastic from which you can cut an insert and file the ends to fit the dovetail cut in the sight, or as kits using epoxy glue and dyes to color it, which are cast into the dovetail.
You can make hard plastic inserts using cheap screwdriver handles as insert material.  This is usually a solvent-proof plastic that makes excellent insert material.  It is a bigger job due to the need to cut a tiny insert out of a large mass of plastic.

If you want to install an insert on as sight that has no dovetail, you'll need to cut a dovetail in the sight.
If the sight is on the gun, use tape to thoroughly tape up the gun so there’s no chance of a missed file stroke scarring the finish or for a vise to scratch it.  Leave only the sight exposed.
The trick is to get the slot toward the top of the sight so when finished and you look through the sights you don’t see any steel above the insert.
To do this, use the EDGE of a large smooth cut file to file a shallow slot in the sight.  The slot doesn't need to be very deep, usually no more than 3/32nd of an inch is plenty.
Using the edge of a file offers more control to keep the slot parallel with the top of the sight.
You can also use a small needle file to file the slot.
Buy an inexpensive triangular needle file and use a stone or bench grinder to remove the cutting surface from one side.  This makes a "safe edge" file that won't cut on that side.
Use the file with the safe edge down to file the undercuts on the ends of the slot to form a dovetail.

Next, install lock holes in the bottom of the dovetail. 
To do this buy a tiny drill bit about 1/2 as wide as the sight blade.
Use a sharp center punch to put two dimples along the bottom of the dovetail, with some space between them.  Use the drill to drill two shallow holes in the sight dovetail.  The center punch marks will prevent the drill from drifting off center.
These holes, when packed with epoxy will form "locks" that will prevent the insert from loosening or getting knocked sideways out of the slot.
In order to practice cutting and shaping the dovetail and drilling the lock holes, buy some 1/8" flat plate at a hardware store and practice making a dovetail on that.
To install a plastic insert, the plastic is cut to shape and a small fine cut file is used to file the ends of the insert to match the dovetail in the sight.
Use a small carbide bit in a Dremel tool to grind a shallow cavity in the underside of the plastic insert.
In combination with the two lock holes in the sight dovetail, the cavity will be filled with epoxy and this will lock the insert in place, even if the plastic is one that epoxy won't stick to very well.

An easier way to fill a dovetail is to use epoxy to cast an insert.
Use a solvent like Acetone, lacquer thinner, or alcohol to degrease the sight.
Make up two "dams" from small, flat pieces of metal or thick plastic.
Apply a coat of wax to the faces of the dams, then clamp them to the sides of the sight blade with a small pair of Vise-Grips to form a mold around the dovetail.
The wax prevents the epoxy from sticking to the dams.  You can use Johnson’s Paste wax or shoe polish wax.

Mix up some 1 to 2 hour type epoxy glue.  The longer cure time gives more working time and allows the epoxy to level in the dovetail.
When mixing the glue, put a SMALL drop of Testor's solvent-base model paint in the glue and mix it thoroughly.
You need only a VERY small amount, and the less you use the stronger the insert will be. If you use too much the insert will be weak and crumbly.
Experiment to find the right mix. Use just enough to color the glue properly.

Use a toothpick or needle to pack the epoxy mix into the holes you drilled in the dovetail, then use a small screwdriver or toothpick to put a drop of the epoxy-paint mix in the dovetail.
You want exactly enough to fill the cut to the top of the sight, level with it but no higher.

Brace the sight, (or the whole gun if it's on the barrel) so the face of the sight is level.
This will allow the epoxy to settle level and not run out.

After the leftover epoxy is like a hard rubber, remove the mold and use a brass or plastic "knife" to clean up any excess epoxy.
Allow to fully cure for 24 hours in a warm place, and you're good to go.

LOOSE INSERTS.
If your front sight insert is loose in the dovetail and you don't want to try to replace it, you can use a small drop of Super Glue to attempt to glue it in place.
Use some alcohol to degrease the sight and dry thoroughly.
Use a liquid super glue, not a gel type on a toothpick to put a small drop on the joint where the insert meets the sight.
Capillary action will draw the glue under the insert.
Quickly press the insert down into place and hold it there until the glue sets up.  Use a small scraper made from brass to scrape off any excess glue.

REPLACING THE FRONT SIGHT
Later Colt revolver front sights were pinned on the barrel with one or two pins.
These pins have "splines" or grooves lengthways of the pin to hold the pin in place.
To change a sight use wood blocks to support the barrel so it can't move or bounce when the pin is driven out.
Use a pin punch slightly smaller than the pins to punch the pins out, from left to right, as you sight down the barrel.
With the pins out the sight will lift out of it's slot, as long as someone hasn't used glue to hold it in place or the slot isn't full of dried lubricant.
If the new sight has the hole already drilled, simply clean out the slot, apply some lubricant to the sight and pins and push the pins back in with a 1/8 inch punch.  The larger punch will prevent the punch from slipping off the pin and scarring the gun.
If the hole is not drilled, insert the sight into the slot, making sure it's bottomed out and positioned properly.
Use a drill the same size as the pins BY HAND to mark the sight where the hole needs to be drilled.
It's not a good idea to drill sight holes by using the holes in the barrel rib as a guide.  If the drill drifts or isn't held perfectly straight, you can easily damage the barrel or enlarge the holes.
Once the sight is marked, remove the sight and use a drill press to actually drill the hole.
After the hole is drilled to the right size, install it in the barrel slot, making sure to drive in the pins the right way around.
These tight fitting pins will often have tiny bits of steel shaved up on the side from which they were driven.  Make sure they go back in with the proper end entering the hole first.
CHANGING THE ACCRO REAR SIGHT BLADE
In the event an Accro rear sight blade can be found, change out procedure is clearly illustrated in the Kuhnhausen shop manual.
The only added advice here, is if the entire sight assembly is removed from the frame, the instant it's removed, wrap some tape around the elevation screw and sight leaf.
The tiny elevation screw retention pin will drop out easily and that allows the elevation screw to drop out, loosing the two super tiny balls and tiny spring.
Don't lose the two small springs on the underside of the sight leaf.
If the elevation screw is removed, use a stiff grease to "glue" the spring and two balls into the screw so they'll stay put during reassembly.

TIGHTENING A LOOSE OLD STYLE EJECTOR ROD HEAD.
Old style ejector rod heads may tend to loosen and can be lost.
To secure the head, use a solvent like Acetone or alcohol to degrease the threads on the rod and the hole in the rod head.  You can use the solvent on a pipe cleaner to clean the hole in the rod head.
After drying, put a small drop of Loctite Blue (temporary) thread locker or a small drop of clear fingernail polish on the threads and screw the head on snugly using a pair of pliers well padded with copper or leather to prevent scratching the metal.

SCREWS VIBRATING LOOSE
Screws in the side plate may tend to vibrate loose.  This is unusual, Colt screws tend to stay tight rather well.
However if a screw loosens the side plate can vibrate loose and cause internal parts to shift out of place.  Worse, if the front side plate screw vibrates loose and isn't noticed, it can scratch a line around the cylinder.
The best way to secure the screws is to use a fitted gunsmith screwdriver to tighten the screws down snug.
A properly tightened screw will seldom come loose, but the trick is understanding that there's a difference between a properly tightened screw and one that's tightened too far and strips the screw or the hole in the frame.
The difference is a matter of experience.  Just tighten the screws down tight, but use common sense.
It's very seldom needed to use any kind of thread locker on side plate screws, and it's recommended not to use any.  This may make screws difficult to remove when needed, and can cause stripped threads.  Also, thread lockers can migrate to other areas and could cause stuck parts.

CAN I CHANGE MY OWN REVOLVER BARREL?
Short answer ..... NO.
Much longer answer explaining WHY not:
Barrel work is a MAJOR pistolsmithing job and requires a considerable amount of very expensive equipment.
It involves a lot of steps that most people, including a surprising number of gunsmiths, don’t even know is required.
Failure to do the job correctly insures an inaccurate revolver at best, and a destroyed frame at worst.
The common do-it-yourself technique is to use “expedient” tooling techniques that are found in old gunsmithing books, and can still be found mentioned occasionally in gun magazines.
These methods range from wrapping rope around the barrel and using it with a stick to form a sort of tourniquet to unscrew the barrel, to the most common, which is to use a hammer handle through the frame window as a “wrench”.
The hammer handle method is to make up a pair of wood barrel blocks for the barrel.
The barrel is sandwiched between the  blocks, and is locked in a shop vice.  One writer said to “Tighten the vise until your eyes bug out”.
A hammer handle or a shaped wooden 2x2 is shoved through the frame and is used as a “wrench” to twist the frame off.
The new barrel is fitted by hand filing the barrel shoulder until the front sight is at 12:00, the rear of the barrel is filed, if necessary, to provide a small gap between the barrel and the cylinder, and you’re off to the range to shoot your fresh re-barrel.

At least that’s how it’s touted as working.
In reality, when the hammer handle is used to turn the frame, one of two things happen:
Either the frame bends, or it breaks.
Revolver frames are a lot softer and easier to bend then most people suspect,  and when the frame itself is used as a wrench, the frame will almost always bend.
Once bent, the frame is ruined even though it may still be shoot-able. 
A bent frame will often have timing problems, and always has alignment problems. All of which cause inaccuracy and possible spitting of bullet metal.
Some owners who’ve tried this method of barrel work, are surprised that the factories do not have some kind of machine or device that will straighten the frame like bent car frames can sometimes be straightened.
The fact is, once bent the frame can never be repaired, and the best a factory can do is replace it.

The second thing that can happen is the frame will break.
If you look at a revolver frame just under the area where the barrel screws in, you’ll see that the frame is very thin in this area.
When the unsupported frame is unscrewed with the handle, the stress can crack it right through the threaded portion.
While there are ways to weld the crack, this requires some special tools to prevent ruining the frame.  The very high expense of having a top level custom pistolsmith/welder do it is very prohibitive, and is reserved for repairs to revolvers of high historical value, with NO guarantee that it will work.
The advice to hand file the barrel shoulder to align the barrel and to file the end of the barrel to provide the barrel/cylinder gap always ruins the barrel, since it’s near impossible to keep the surfaces perfectly square with a hand file.
The result is tilted barrels due to uneven shoulders, and the end of the barrel not square with the cylinder.

When re-barreling a revolver, the first thing you need is a USABLE barrel.
New Colt barrels of any type are becoming impossible to find.
Getting a good, used barrel is much harder to get then you’d think, since a good percentage of barrels for sale at gun shows and on auctions are defective.
Major reasons for selling a used barrel are, the barrel was defective to start with, or it was damaged during removal using the hammer handle method.
This damage may not always be readily apparent, and sometimes isn’t revealed until the pistolsmith attempts to install it.
Damage can run from tiny cracks in the forcing cone to pitted bores, to bent barrels.
Cracks in the forcing cone are common, and contrary to popular opinion, a cracked barrel is almost always toast.
Cracks in steel tend to continue to spread, even if you cut the cracked end off, since cracks are a sign of metal fatigue caused by blast damage.
Some gunsmiths will attempt to save a barrel with a cracked forcing cone by setting the barrel back, but this almost always fails, and the crack continues to spread forward.

Here’s a brief description of how a revolver barrel is changed correctly:
First, the barrel is locked in a special barrel vise.
This may be the hydraulic jack type vises that gunsmiths use to change out rifle barrels or a modified large shop vise.
The actual barrel blocks can be custom machined brass or aluminum barrel inserts that are fitted to specific makes and models.
As example the pistolsmith will have one set for Pythons, others for Trooper Mark III’s, King Cobras, shrouded Detective Specials, etc, and sets for use on the round barrel types.

These inserts are installed around the barrel, then clamped in the barrel vise.
The action, or frame wrench, is installed on the frame.
This wrench is a universal revolver wrench that fits around the front of the frame.  It is fitted with brand and type specific hard plastic inserts.
These inserts very closely fit the front of the frame around and below the barrel area to fully support the frame.
The pistolsmith will have inserts for specific guns.  As example one set for Colt “E & I” frames, another set for “J” frames, another set for “D” frames, etc.
These inserts support the frame and spread the torque over a wider area to allow unscrewing the frame without over stressing the frame and damaging it.
With the frame and barrel tightly locked up, and with no “spring” to the setup, the barrel is unscrewed by rotating the frame wrench.

With the barrel off, the frame threads are cleaned up with brass brushes, solvent, and if necessary are “chased” with a tap to insure clean, uniform threads.
The replacement barrel is closely inspected and it’s threads are cleaned and chased with a die if necessary.
The barrel is test fitted to the frame to determine where the front sight is and how much material has to be removed to allow the front sight to be at 12:00 top-dead-center after being torqued in place.
How much to remove is largely a judgment call based on experience.
Using a lathe or a bench trimming device, that amount of metal is removed from the barrel shoulder.

The barrel threads are coated with anti-seize compound and the barrel is threaded on the frame, everything is relocked in the barrel vise and frame wrench, and the barrel is torqued in place.
If the barrel is torqued with insufficient torque the barrel will vibrate loose.
Too much and you run the risk of pressure dimpling or constricting the bore in the thread area, or even cracking the frame.

With the barrel in place, the barrel/cylinder gap must be set.
This is done with a special cutter tool that works down the bore.
A Tee-handle rod is put down the bore and a cutter tool is attached on the end.  The rod is pulled outward and rotated, trimming the rear end of the barrel.
Care has to be taken to insure the end of the barrel is not scalloped from uneven pressure.
With the barrel/cylinder gap set to an ideal .005”, the forcing cone has to be re-cut.

The forcing cone is very misunderstood, and even some gunsmiths have no idea it has to be re-cut and gauged or that it must be gauged at all.
The critical dimension of the cone is not it’s “length” or taper, but the outer diameter of the mouth.
If the outer mouth is too big, the gun will be inaccurate.  Too small and it’s inaccurate and will spit bullet metal.
The same Tee handle tool is inserted down the bore, but this time a cone-shaped cutter head is attached.
The cutter heads come in various tapers, and you can set a barrel for exclusive use with lead bullets by using a longer taper, or for jacketed with shorter tapers.
The factories use a good compromise that works with everything.

The Tee handle is pulled outward, pulling the cutter into the forcing cone.  The handle is rotated and the cutter head cuts the cone.
Again, care is taken to prevent scalloping and the progress is checked often with a special plug gauge.
This drop-in plug gauge gauges the outer diameter of the cone.  The difference between too large and too small is very small, so gauging is done often.
The cone cannot be "eyeballed", it has to be gauged with the plug gauge.

After the cone is cut, yet another head is attached to the Tee handle, this time a brass cone-shaped lapping head.
Valve grinding compound is applied to the lap, and the forcing cone is lapped to a smooth finish.
After lapping, the barrel and frame is carefully cleaned of all metal chips and lapping compound, and the revolver is reassembled.
The last step is firing the revolver for function, and to check accuracy off the sandbags.
As you can see, there’s a LOT more involved than first thought, and all steps are CRITICAL.
Unless you’re willing to invest quite a bit of money in custom made tooling and spend the time learning how to properly use it, attempting a do-it-yourself re-barrel job is a very fast way to ruin a good gun.

CAN I CHANGE MY CYLINDER?
Short answer....NO.
Longer answer why not:

Again, revolvers are very old school.  Unlike automatic pistols, most parts can't be installed without considerable fitting and adjustment.
No revolver part is more fitted and adjusted than the cylinder assembly.
Just because a cylinder will snap into the frame and seems to work is no guarantee that it really fits correctly.
Due to variations in frames and cylinders and ejectors, it's very possible a used cylinder assembly can't be fitted at all.
This is where the amateur gunsmith, having sunk good money in a cylinder that won't fit is tempted to MAKE it fit, and in so doing ruins a good gun.
The first step in installing a different cylinder is that you need a cylinder assembly of a cylinder and a new ejector.
A used ejector may be too short to be used at all, and there's no way to stretch one.
First the ejector is fitted to the cylinder to make sure the ejector doesn't overlap a chamber and it's properly aligned in the cylinder.
That cylinder assembly is then fitted to the cylinder crane, and that entire assembly is then fitted to the frame.
The ejector is precision trimmed on the rear face to set proper head space using a precision surface grinder or a lathe or milling machine.
Then the assembly is checked and adjusted for cylinder end shake and barrel-cylinder gap.
With all that set, the assembly is checked for chamber-barrel alignment on all chambers and timing on all chambers.
If anything is off, it takes a master gunsmith to know how to adjust things, or who understands that it's time to get a different assembly that will work.

REMOVING THE SIDE PLATE
An older Colt may be badly fouled or impacted with dried or gummy old lubricants.
In order to clean the action it may be desirable to remove the side plate to access the interior for a good cleaning.  This too can be a problem since interior parts can shift out of position, making reassembly difficult.
Revolver side plates MUST be removed properly and with great care.  Failing to do it the right way can spring side plates and cause dents and chatter marks on plates and frames.

First step is to remove the grips and the cylinder assembly.
With those off, unscrew and remove both side plate screws, using a fitted gunsmith's screwdriver bit. 
Keep the screws separated so they go back in the same hole. 
Older Colt's and models with Service type grips have two screws with rounded dome heads.  The screw in the rear of the plate is slightly shorter then the front screw.
On revolvers fitted with Target grips, the rear screw has a flat head.
The new style Mark III and later revolvers have a larger dome head screw on the front of the side plate, the rear screw is a long bolt that screws into a nut that's pressed into the frame on the right side.  Don't remove the nut unless for replacement.

With the screws out, hold your finger on the front of the cylinder release to prevent it from popping off.
Use the end of a plastic screwdriver to give the grip frame below the side plate sharp raps.  This will vibrate the side plate loose so it can be lifted off.
NEVER pry on the plate, this will seriously damage it and the frame. 
If the plate is resistant, apply some Kroil or other penetrating fluid around the side plate joints and allow to soak over night.

When the side plate is lifted off, slide the cylinder release forward and off, and remove the tiny spring and plunger from the tunnel in the side plate under the release.
On the new style models, the spring that powers the cylinder release is a "Z" spring that lays in a recess under the latch.  Lift it out after sliding the cylinder release off.

To reinstall the plate on the old style action, insert the release spring and plunger into the side plate, then slide the release onto the plate.
Make sure the cylinder latch pin that protrudes through the breech face is all the way forward and the release pin is in the notch on the frame.
Sliding the cylinder release slightly to the rear, slip the top of the side plate into position on the frame, and gently push the plate down into position, making sure the cylinder release fits over the cylinder release pin.
If the plate won't fit into the frame, DON'T FORCE IT.  Something is out of place.
Either the cylinder release pin has rotated out of the notch, the cylinder release isn't properly fitting over the pin, or the hand that rotates the cylinder has moved up out of position with the rebound lever.

The new style action models have a transfer bar system.  The transfer bar and the hand both fit over pins on the trigger.  These parts will almost always come off the pins during side plate removal.
Install the cylinder release "Z" spring into the recess in the side plate and slip the cylinder release into position.
During reassembly, the hand goes on the front trigger pin, the transfer bar on the rear pin with the transfer bar spring resting on the back of the hand.  The plate must be gently installed to prevent these parts from popping off the pins.
Once the plate is properly in position, hold the plate down into the frame and operate the action to insure everything is working properly.
Install the side plate screws in the hole they came out of and snug them down with the screwdriver.  Tighten the screws enough to insure they stay put but take care not to strip the threads.
It's recommended that before removing the side plate you buy the Kuhnhausen shop manual appropriate to your model.  This fully illustrates side plate removal and re-installation.

TRIGGER AND ACTION WORK
Attempting to lighten or smooth out a Colt trigger action is one of the most abused gunsmithing jobs of them all.
Over the years various magazine articles and older gunsmithing books describe various techniques for action work, but these are either no longer considered to be valid methods, or fail to fully explain what's actually needed to do it correctly.
A classic symptom of a botched trigger job on the Colt revolver, especially on the older models is that the revolver reliably fires in single action, but mis-fires in double action.
This is caused by incorrectly bending the "vee" mainspring on the older models, and either cutting coils off the mainspring on the newer models, or installing a lighter weight mainspring that's too light. 

There's a common belief that the lighter a trigger pull is, the "better" the trigger.  Too many people over-lighten triggers trying for the lightest pull possible and wind up with an unreliable revolver.
Super light single action triggers have a place on the formal target line or in a range toy, but NOT in a defense or general use revolver.
Today, we understand that the best trigger is a SMOOTH trigger action.  A smooth trigger action feels lighter, but will retain the reliable operation required on a revolver used for serious purposes like defense.
Many of today's speed shooters actually install STRONGER springs, since a revolver with a light trigger pull is actually slower to fire due to the reduced tension.  A trigger that's too light can also cause "short stroking" or trigger re-set problems.  With a too-light trigger pull the shooter may fail to allow the trigger to move far enough forward and attempt to pull it again before it's re-set itself. 
Given the choice between a lighter trigger action and a smoother action, today's smart shooter chooses a smoother trigger.

"POLISHING" GUN PARTS AND LIGHTENING THE TRIGGER PULL
You'll often hear references to "polishing" gun parts to give smoother operation.
When a gunsmith says "polish" what he actually means is to SMOOTH a working surface.
Too many people hear "polish" and think "like a mirror".
Polishing a gun part to a mirror shine does absolutely no good at all and is one of the most common causes of ruined parts.
In order to get a mirror shine too much metal must be polished off the surface, which may under-size it and ruin the part or break through the surface hardening.
On the older types of Colt's some parts can be lightly smoothed or "polished" to remove machine marks left by the machining process.  All that's needed is to smooth the part just enough that critical surfaces don't catch or stick.  The key part of this is that ONLY the critical surfaces that will benefit are worked on, and no others.
What parts that may benefit from light smoothing are described in the Kuhnhausen shop manuals.

Actually smoothing the action of an old style Colt is best left to an expert, since the small working surfaces are easily ruined by improper work.
One valid technique of lightening the Colt "vee" mainspring is to insert a rod between the legs of the spring and cocking the hammer.  This puts a slight downward bend in the upper leg and lightens both single action and double action pull.
However, this is very often incorrectly done and causes mis-fires.  Too many people hearing about this method just shove in whatever punch or rod is handy and wind up with a trigger that's too light.

The correct method is to use an accurate trigger pull gauge to measure the pull.  This allows bending the spring with out going below the minimums.
This method starts out with a small rod, such as the shank of a small drill.  The spring is bent and the trigger pull is gauged in both double action and single action.  If both pull weights are above the factory minimums a slightly larger rod is used.  Once both pulls begin to approach the factory minimums, stop before you get under the minimum weights.  If you go under, you may have to try to find a new spring, or have to disassemble the action to re-bend the spring.

Trigger work on the newer Colt revolvers like the Mark III series and later is limited to installation of lighter weight mainsprings and trigger return springs.
These usually come in kits with a lighter trigger return spring and several different weight mainsprings.
Due to the very thin surface hardening of these models action parts, they CANNOT be polished or altered to give a lighter pull.
Since these parts are made of high precision molded parts there are no machine marks or roughness, the critical work surfaces are already as smooth as possible and attempting to further smooth them will have no effect other than to ruin them by breaking through the surface hardening, exposing the soft steel underneath.
Since the trigger return spring not only powers the trigger, it also powers the critical transfer bar which is also the revolvers safety device that prevents firing unless the trigger is deliberately pulled.  Installing too light a trigger spring or altering a trigger spring can not only prevent trigger return, it can also prevent the transfer bar safety from working, resulting in an accidental discharge.

In all cases of doing any trigger or action work on any Colt revolver the standards are that the trigger pull in both single action and double action cannot be below factory specified minimums, AND that the revolver be 100% reliable in both single action and double action.
The final test is to actually shoot the revolver to verify that it's reliable.
When dealing with a defense revolver, lightening the trigger is not recommended at all.
The test is to shoot at least 100 rounds of the same ammunition that will be carried in it.  Shooting some other ammunition will not give a valid verification.
If you want a lighter or smoother trigger in a Colt, Colt Firearms offer trigger work at reasonable prices on most Colt revolvers.
As example, they offer two levels of work on the Python.  The Target level is to be used only with .38 Special ammunition because the gun will not be reliable with Magnum ammunition.  The second level of Python work is a Service level that will be reliable with Magnum ammunition’s harder primers.
Other custom gunsmiths also offer trigger work, although most of the old Master gunsmiths who offered superb Colt trigger work are now gone.

COLT TRIGGER PULL SPECIFICATIONS
Factory specified trigger pulls for Colt revolvers are as follows:
Factory specified single action pull:
Model                               Minimum      Maximum
"D" frame .22 caliber         3.0 lbs           5.0 lbs
"D" frame .32 caliber         3.0 lbs           5.0 lbs
"D" frame .38 caliber         3.0 lbs           5.0 lbs  Note: The Agent max is 7.0 lbs
"E" frame .32 caliber          3.0 lbs           4.5 lbs
"E" frame .38 caliber          3.0 lbs           4.5 lbs      
"I" frame 38 caliber            2.5 lbs           4.5 lbs
"I" frame .357 caliber         2.5 lbs           4.5 lbs

Factory double action pull.
                                           Maximum
"D" frame .22 caliber          14 lbs   
"D" frame .32 caliber          14 lbs
"D" frame .38 caliber          14 lbs
"E" .32 caliber                     14 lbs
"E" .38 caliber                     14 lbs
"I" .38 caliber                      12 lbs
"I" .357 caliber                    12 lbs

Factory specified single action pull for the Mark III and later Colt's
Minimum        Maximum
3.0 lbs              5.0 lbs
 
Factory specified double action pull for the Mark III and later Colt's
Maximum
14.0 lbs.

COLD BLUING SCRATCHES AND WEAR.
Bluing is a beautiful, traditional finish and no gun maker did a better job than Colt.  Unfortunately, like most gun finishes bluing is not all that durable.  It wears off due to handling and holstering, and picks up scratches.
A gun owner would like to keep his Colt looking factory new, but the only way to do that is to put the gun in a glass case and never touch it.
Any gun that gets handled or used at all will develop finish damage.
It's possible to touch up this damage by using one of the cold blues but there are some things to know first.
Cold blues are intended to be used to touch up small areas where the bluing has worn off or to color scratches.  They were never intended to be used to re-blue large areas or complete guns. 
Colt blues darken steel by an acid chemical reaction that gives the steel a blue-black color.
This is no where even close to matching the factory blued finish, and is not durable at all.  This coloring of the steel can be wiped off by rubbing it a few times with a finger.
Because of the chemicals used in cold blues, cold blue can actually cause the area to rust.
Colt blues tend to turn brown, often within a few weeks.
Cold blues will leave a discolored blotch in the original bluing around the area where cold blue was used and may make the area look worse.
While they can and have been used to re-blue entire guns, the same problems remain; a finish that's not durable and doesn't have the dark blue-black color of a factory
blue job.

COLD BLUES.
There's a number of brands and types of cold blues, including liquids, creams, and "pencils" filled with cold blue.
Brownell's sell most of the better cold blues.
Brownell's own Oxpho-Blue, 44/40, and Dicrophan T-4 all have the best reputations for quality of results.
The key to getting the best results is that the metal absolutely must be as clean and free of oils as possible.
What's needed are solvents that clean off the metal, then evaporate leaving no residue at all.
Denatured alcohol, 95% isopropyl alcohol, Acetone, carburetor cleaner, and electric motor cleaner can all be used, but be very careful to test the cleaner in a hidden spot.  Some chemicals can remove or damage bluing.

Once the area is as clean as possible, apply the cold blue per the directions on the container.
Some people have had good results by using 0000 steel wool to apply the cold blue, rubbing the coat on lightly with the steel wool.
Steel wool is soaked in an oil to prevent it from rusting.  That oil can contaminate the area and prevent getting good results.
In order to prevent contamination, first soak a small ball of the 0000 steel wool in alcohol to remove the oil and allow the steel wool to air dry before using.
Others prefer cotton swabs or cotton balls, depending on how big the area is.
For scratches, using an fine artist's brush will allow applying the cold blue to only the scratch and keep it from discoloring the bluing around the scratch.
Multiple coats may be applied to get as dark a color as possible.
The metal must be thoroughly rinsed per the directions to get all the residue off the metal, or the metal will rust later.
After the bluing is complete a coat of a good rust preventing lubricant must be applied to prevent rust.
After using cold blue, the owner is well advised to keep a close watch on the gun for at least a few weeks to catch it in time if the cold blued area starts to develop rust.