Korth announced a new 9mm conversion kit to transform a Smith & Wesson L-frame revolver chambered in .357 Magnum. The conversion allows for the use of 9mm “rimless” cartridges in the revolver without needing a moon clip.
The conversion kit comes with the cylinder assembly and speed loader. To convert the gun, all one has to do is remove the lock screw that holds the cylinder assembly in the gun. Then slide out the old cylinder and replace it with the new. Tighten the screw down and that’s it: you now have a 9mm revolver.
The key to efficiently operating a revolver with rimless cartridges is the extraction of the fired shells. When a round is fired, the case expands and creates a tight fit inside the charge hole. The extractor star on a normal revolver pulls the empty case out and allows it to drop free. With a rimless cartridge such as the 9mm, there is no overhanging rim for the typical extractor to use to yank the spent case from the chamber.
Another problem with the 9mm is that the case is tapered. This means that an unfired round has relatively little contact with the inside of the chamber and can back out during fire. A round that backs out of the cylinder can lock up a revolver. This will prevent the gun from firing until the “jam” is cleared.
Typically, the use of a thin piece of metal – a moon clip – would be used to overcome these problems. A moon clip requires the shooter to snap cartridges into it. Then all of the cartridges are inserted and extracted en masse. This system works well for many shooters, and I found it worked well with the Taurus 905 9mm revolver I previously reviewed. Revolver master Jerry Miculek has used these kinds of guns to win competitions and set world records.
However, a number of companies have tried – with varying success – to create revolvers that will run rimless cartridges without a moon clip. A number of decades ago Smith & Wesson did it with the model 547 built on a K-frame.
In more modern times, Charter Arms has made the Pitbull. The Pitbull is a series of revolvers that are chambered for the 9mm, .40 S&W and .45 ACP. While my experience with the guns have been mixed, some people like them a lot. My main issue with the Pitbull was reliable extraction.
Korth has not listed a MSRP on the conversion kits. If the kits are reliable and reasonably priced, I could see the company selling quite a few of them.
It is true that the 9mm doesn’t offer a lot that the .357 Magnum won’t do, but there are some self defense cartridges that simply are not made in the Magnum caliber. Also there are a number of odd people like me that just like doing weird things – like shooting 9mm from a revolver.