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.