How to work on dual-caliber cylinders and conversion cylinders to improve revolvers and increase the chamberings used.

by RK Campbell

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 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 a way 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.

Read more in the February 2020 issue.

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