Homespun Cartridge Conversion, Part 1


Having just competed The Outlaw I was left with a cap-and-ball cylinder I had no use for and a metal lathe that was doing nothing particular at that moment. Hmmm… I wonder if I can bore this out to shoot the original .44 Colt?* I pulled the nipples, chucked up the cylinder and turned down the back around the ratchet so it would fit the gated ring that came with the Kirst Konverter. Well, that’s what I meant to do… It actually came out a bit small. No matter, I can always make a pass-through breech plate.

Rummaging around in Uncle Jim’s tool box I came up with a .450 drill bit. I set up the milling vice in the drill press, grabbed the cutting fluid and away I went. No real issues drilling out the soft steel cylinder- until I discovered it had broken through the base of the cylinder lock notch.

Oh dear… well, nothing ventured, nothing gained and it’s not like I was going to use it… Fast forward to this morning. We had electricians running power in for the milling machine (finally!) so I was very limited in what sort of work I could do. I finished the few odds and ends I could manage without interfering with the workers and had a smoke while I contemplated what to do next. My eye fell on the ruined cylinder and something occurred to me- while I couldn’t cut chambers for .44 Colt that wasn’t the only caliber in the world. As it happened there was 16″ of .357 barrel-liner lying on the bench that I had been wondering what to do with. A barrel liner that just happened to have a nominal outside diameter of .444″.

The drill press wouldn’t produce dust and since it is in the corner opposite where the electricians were working I could see no reason not to bore out another chamber or five. Thirty minutes and a half-cup of cutting fluid later all six chambers were bored through, and yep-every one of them broke through the locking notch. No matter. Off to the bandsaw (which was only a little bit in the way) to cut a two-inch section of barrel-liner. With the help of a handy hammer and an immoderate amount of pounding I was able to get the liner into one of the chambers.

Success! I trimmed off the excess and repeated the process five more times. Now I had a cylinder with six lined chambers. Uh… rifled chambers. Yeah, that’s not right. Back to the drill-press. I bored all six chambers with a .355″ drill, dressed the front of the cylinder and with some judicious filing got the back fixed up. Sweat in some silver solder, dress the back of the cylinder and it’ll ready for the chamber reamer!

OK, some of those holes aren’t perfectly straight, which was some concern to me until I measure a couple of cylinders I have lying around and found they were pretty damn close to what the factory produced. Certainly they will line up with the forcing cone well enough, and I happen to have a buddy with a forcing-cone reamer who lives nearby.

Those of you acquainted with basic math will note that I still have 4″ of barrel liner left, so if I happen across a Pietta .44 or .36 yearning to be a short-barreled cartridge conversion I’m all set. Next I need to make the base-plate. This will have a simple pass-through rather than an actual gate. No point in pushing it… this time.

*Modern .44 Colt uses a .429 diameter bullet and will not work in a .44 cartridge conversion. Like the originals .44 C&B reproductions are actually .45 Caliber with a .451-.454 bore. The original .44 Colt used a .451 heeled bullet with the same outside diameter at the front as the cartridge case and a .430 heeled base. Sort of like a .22 on steroids.

Michael Tinker Pearce, 18 August 2017

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