Converting Revolver Cylinders

Among the most interesting and useful revolvers are those that are chambered for more than one cartridge by use of a replacement or conversion cylinder. Among the most common combinations are .38-40/10mm, .32-20/.32 H&R Magnum, and .45 ACP/.45 Colt. The most common by far are the .22 Magnum/.22 Long Rifle designs. Due to the ease of changing cylinders by simply removing a cylinder base pin, single action revolvers are the most common revolvers with dual cylinders.

There have been occasional attempts at dual cylinder double action revolvers from the factory but they are more rare. And then there are revolvers such as the Smith & Wesson 1917 handgun which use a single cylinder designed to accept two cartridge types: .45 Automatic Colt Pistol and the .45 Auto Rim. Conversion cylinders are not particularly difficult to deal with.

Over time I have experienced problems with both single action and double action revolvers and repaired them without any difficulty related to the cylinders. The difference between the types, however, must be understood. I would recommend anyone interested in a dual cylinder revolver purchase a factory version. This is much less trouble than obtaining an aftermarket cylinder and fitting it. However, some folks are what I call "real shooters"—and I guess I am one of them.

It isn’t all about economy but An important point when working with different chamberings. about a pleasant, even immensely interesting, shooting experience. Expense is a secondary consideration. If someone has a .45 Colt single action revolver and wishes to own a .45 ACP cylinder then they will find away to get it done. The .45 ACP offers real economy and ease of handloading compared to the .45 Colt while offering enough power for most uses. The most useful combination overall is the .22 LR/.22 Magnum.

Some of the others are simply interesting. If you own a revolver that originally had both cylinders and one is lost, it is possible to fit a spare cylinder to the revolver. If the revolver never was supplied with a spare cylinder in a different caliber, then you may have a bit more difficulty in fitting the cylinder. Let’s look at the problems and fixes I have encountered. Single Action .45 ACP Cylinder We’ll start with fitting a .45 ACP cylinder to a .45 Colt caliber Single Action Army-type revolver.

I have never fitted a .45 ACP cylinder to a Colt, however, I have fitted several Uberti types. I would imagine the Colt would be reasonably close in dimensions, but the two Uberti revolvers I encountered were not each exactly the same. This is to be expected. After all, Uberti may manufacture a run of brass frame revolvers for one importer designed for a low price point, while the Cimarron revolvers imported from Uberti will be beautiful specimens.

I am certain that a certain deviation in exact measurements in a quality revolver demanding hand fitting is inevitable. Occasionally, aftermarket cylinders in .45 ACP show up for the SAA .45

45 ACP and .45 Colt single action revolver cylinders must have different ratchets. The factory product usually works well. Taking your time in fitting cylinders to other revolvers is important. 45 ACP (left) headspaces on the case mouth. The .45 Colt headspaces on the cartridge case rim. Colt revolver. As recently as June 2019, Midway USA listed .45 ACP Uberti cylinders in stock on their website. The Ruger Blackhawk is fairly common with a .45 Colt/.45 ACP cylinder combination, the .357/9mm less so.

The SAA "Cowboy" types are far less common. Many users never change the cylinders out and fire .45 Colt exclusively while some make extensive use of the .45 ACP cylinder. Perhaps the makers made over runs and the cylinder is available. The Uberti type in particular is very uncommon. As it was, I found a .45 Colt Dakota revolver on my desk along with a .45 ACP cylinder. When the .45 ACP Uberti cylinder arrived, I degreased it. I wanted it clean but dry.

Next, I carefully removed the .45 Colt cylinder from the customer’s Uberti. This is accomplished by opening the loading gate, removing the base pin, and placing the revolver on half cock. The cylinder more or less pushes out. I then carefully attempted to fit the cylinder into the frame window. It did not fit the revolver. It wasn’t even close. The problem in general is that .45 ACP cylinders are slightly longer than .45 Colt cylinders—at least this one was.

When you take a look at the .45 Colt and .45 ACP case rims under magnification, you’ll see that while .45 Colt doesn’t have a heavy cartridge case rim like the .44 Special, it does have a standard revolver cartridge case rim. There isn’t much need for a heavy rim in a button or rod ejecting revolver versus a star-type ejecting revolver. The .45 ACP is rimless The .45 ACP and .45 Colt is a good example. and has an extractor groove for extraction from the automatic pistol.

The button ejecting single action revolver works just fine with this set up. The .45 ACP headspaces on the cartridge case mouth, revolver cartridges headspace on the cartridge case rim. The cylinder must set a bit closer to the firing pin with the .45 ACP and need not be relived as much for the .45 Colt. When I began attempting to fit the .45 ACP cylinder into the Dakota it seemed to be bumping into a raised area on the left rear of the frame.

I studied this for some time and determined that filing the ridge would not affect function with the .45 Colt cylinder. It was carefully filed, cleaned, and trial attempted to place the cylinder into the revolver before repeating again. This was all that was needed for the cylinder to set into the frame window. The diameter of the .45 ACP cylinder was the same as the .45 Colt, however, the ratchet was a bit larger in diameter. The .45 ACP cylinder ratchet measured 0.590 versus 0.550 for the .45 Colt cylinder.

Just the same, the cylinder now locked in and worked fine. Occasionally, a conversion like this will demand end shake bushings to move the cylinder to the rear which are fitted over the cylinder bushing. Brownells offers these. It is a good idea to use Loctite to secure these end shake bushings so they do not fall from the cylinder when the cylinder is changed out. As for the customer’s satisfaction, he has not used the .45 Colt cylinder since obtaining the .45 ACP.

My slight file work did not affect the fit of the .45 Colt revolver cylinder. A note on accuracy standards. It isn’t unusual for older revolv-

45 ACP cylinder. 45 Colt is a grand old cartridge. For most of us, the .45 ACP is more economical and readily available. ers—and we are talking about one hundred years ago—to have a bore diameter of 0.452 to 0.454 in .45 Colt. Both .45 ACP revolvers and self-loading handguns generally run 0.451. Modern revolvers, with few exceptions, have a 0.451" bore in both .45 ACP and .45 Colt. So, 0.451" jacketed bullets and 0.452" lead bullets will work just fine.

If you fit a .45 ACP cylinder to an old Colt with the more generous bore dimensions I am certain that cast lead bullets need to be a larger diameter for good accuracy. Anyone asking for this type of conversion is apt to be a knowledgeable shooter, but just the same, a good discussion is in order before beginning. Smith & Wesson 1917 The story of the Smith & Wesson 1917 is a thrice told tale I will repeat again.

Before the United States entered World War I, Britain was hard-pressed for handguns and purchased thousands of Colt and Smith & Wesson revolvers in .455 Webley. When America entered the war, we had perhaps 30,000 1911 handguns. We needed to arm every troop for what was shaping up as a pistol war and a million man army. Colt simply could not fill the need for 1911 handguns and neither could Remington UMC or other contractors.

Smith & Wesson had production capacity geared up and simply re-chambered their big frame revolvers for the .45 ACP cartridge. Since the .45 automatic cartridge does not have a cartridgecase rim, the rounds simply fell into the cylinder. After early testing, a properly chambering cylinder design was implemented, although the ejector star would not eject a rimless cartridge. Smith & Wesson developed the half-moon clip which held three cartridges.

Those clips neatly solved the problem of using a self-loader’s cartridge in the revolver by providing headspace with the 0.050-inch thick clips. .45 ACP cartridges were issued in half-moon clips to avoid having two handgun calibers in the supply chain. While some moon clips may not be suitable for long, hard use, Ranch Products (RanchProducts.com, and Wilson Combat (WilsonCombat.com, offer famously reliable moon clips. Some shooters firing these revolvers have complaints with accuracy.

The 200 grain SWC is more accurate than the 230 grain RNL bullet in handloads. It seems the shorter RNL bullet may tip in the long jump from the cartridge mouth to the forcing case. The 255 grain SWC is more accurate than the 200 grain bullet. Just the same, this is a service gun not a target gun. The .45 ACP for some reason seems more accurate and reliable when fired in moon clips. There is the occasional misfire of the .45 ACP that results in low powder ignition and a bullet stuck in the barrel.

Keeping an eye on end shake and using moon clips may help with this un-

22 Long Rifle/.22 Magnum. This is the Heritage Rough Rider. common but documented problem. As an aside, a young friend that is a serious competition shooter has experienced similar problems with 9mm revolvers, including bullets jumping the cartridge case in recoil. After all, these cartridges weren’t meant for revolvers but not all such ammunition is subject to this problem. I recently examined a Smith & Wesson Model 1937, a later variation of the 1917 manufactured for the Brazilian military.

The revolver had unusual burrs in the bolt stop cut in the cylinder. They could be polished out but the real question was, what caused it? I cocked the hammer and found the bolt stop seemed to operate normally. The It isn’t possible to do a touch up properly. It wasn’t difficult to fit. trigger and hammer seemed in time and the bolt stop window was OK by eye. The hand seemed normal. Finally, I asked how fast the man was shooting?

I am not saying he rivals Jerry Miculek, but he is very fast, shoots a lot of IDPA, and loves his 1917 revolver. The cylinder is moving pretty quickly when the bolt stop drops into the notch. I have timed splits (time between shots) among competitors as fast as 0.35 second. My range is more often 0.6 second. The famous exhibition and competition shooter Miculek runs around 0.125. The late Elmer Keith practiced a great deal of practical double action shooting.

He noted that if the action were too light he could "tie up" a DA revolver. So, the shooter in this case was advised to slow down. The revolver’s burrs and nicks were polished and cold blued. They did not reoccur. The old, smooth, long action Smith & Wesson were nice examples of hand fitting but the modern short action is the better choice for fast shooting. Another choice for these revolvers is the .45 Auto Rim cartridge. After World War I many 1917 revolvers were sold as surplus.

Since most shooters did not wish to fiddle with moon clips, Remington Peters developed the .45 Auto Rim, which is simply a .45 ACP case with a thick revolver rim. This is a strong cartridge case that allows handloaders to put together loads suitable for thin skinned game. Buffalo Bore Ammunition (Buffalo Bore. com, offers quality factory ammunition. The .45 Auto Rim will not chamber in single action revolver .45 ACP cylinders due to headspace and it will not work in the Taurus .45 ACP Tracker.

This information will help shooters avoid unnecessary purchases of ammunition that will not function in their revolver, though I’m certain .45 ACP in a revolver in general isn’t for the slightly interested shooter. .22 Caliber Cylinders In my experience, Ruger cylinders are fitted to each handgun and not interchangeable. The same goes for the Heritage line, a well made and reliable but affordable revolver.

Quite often, a gun shows up in the gun store without the spare cylinder, with someone using one cylinder and losing the other. After all, how many used guns still have the box or original papers? I have fitted a few of these cylinders, perhaps three in thirty years. To check availability and the practical sense of such an operation, I looked for a conversion cylinder for sale

45 ACP Model 1917/37 revolver. They are generally among the most robust of revolvers. and found a .22 Magnum cylinder for the Heritage revolver for sale on e Bay for $40. A quick check at South Carolina Gun Company (SCgun Co. com, confirmed that a standard Heritage .22 Long Rifle revolver new in the box is $129 retail while the revolver with a spare cylinder is $152. Used revolvers are twenty per cent less. For $23 more dollars the factory version is the much better buy.

Still, if someone has a .22 LR revolver they like, I suppose it is OK to fit a .22 Magnum cylinder. The .22 LR GO headspace gauge is 0.043 while the rim thickness of most .22 LR measures 0.037 to 0.042. Barrel and cylinder gap is often 0.010 on these revolvers. Some are tighter. Headspace is adjusted by polishing the rear of the cylinder to be fitted. This applies to anew cylinder. If it has been in use in another revolver, it may not be long enough to be fitted to another revolver.

If the barrel cylinder gap is tight, you may then slightly file the rear of the barrel. If too loose, the standard procedure to correct gap is to set the barrel back a thread and re cut the forcing cone. This is far too expensive to attempt with such an inexpensive revolver. I would be very leery of turning the barrel in the frame of the zinc/alloy Heritage, Chiappa, or Ruger Wrangler revolvers. Having a revolver that offers the use of more than one cartridge is desirable for many of us.

Firing inexpensive .22 LR in a revolver and then using the powerful .22 Magnum for hunting is useful. The .45 Colt is more difficult to successfully handload than the .45 ACP as it was originally designed for black powder loads. Blow-by and a full powder burn are considerations. The .45 In most situations there is no cause for concern. ACP is more economical and easier to handload and powerful enough for most uses. The .45 ACP 1917 type isn’t a dual cylinder revolver but certainly a dual caliber revolver.

These are interesting handguns and respond well to gunsmithing. A New Trick I wish I could provide exact dimensions for this new trick but I am just investigating the procedure and do not have the guns on hand. However, it is possible; viable, but likely too expensive for many shooters. Some time ago, .455 Webley ammunition was impossible to find. Hornady offers an excellent quality reproduction load as does Fiocchi Ammunition. Availability varies but if you look hard enough you will find the loads.

The .455 Webley revolver was commonly faced off at the rear of the cylinder to accept .45 ACP moon clips. Since the .455 throws a 265 grain bullet at 655 fps this may be a questionable conversion unless the shooter keeps his .45 ACP loads quite modest. I am certain the strong double action Smith & Wesson revolvers are fine with loads a bit stronger than the .455, but perhaps not the Webley break top revolvers. Sight regulation may also be a problem.

Today, very few original .455 Webley revolvers exist as most were converted. The Smith & Wesson and Colt revolvers issued to the Brits also were converted although the Webley seems more common. A neat machining project is to machine a disk that allows the chambering of the .455 Webley. This disk fits on the back of the cylinder. It replaces the moon clips once used and allows firing the .455 Webley again.

Author John Taffin tells us that two moon clips were too thick and that both he and the gunsmith involved agreed the work was too expensive. For those of you with time and skill, this just may be a good project. AG