The Walker Cartridge Conversion

Last year I came up with the idea of converting a Walker reproduction to something a bit stronger than .45 Colt. After all, the original load for the Walker was a 210gr. Pickett bullet over 60 gr. of black powder; that’s 50% more powder that a .45 Colt… Of course people immediately informed me that it had been done- the .45 BPM, .45 Walker, .45 Brimstone etc.  OK, that meant I knew it could be done. A buddy of mine found an Armi San Marcos Walker repro at a good price and I snagged it.  So far so good.


God, what a beast! 4-1/2 pounds of Italian steel.  I prefer a more compact package, so I cut the barrel at the lug, giving me 3-1/2″ of barrel. That took a full pound off the weight… better. I re-crowned the barrel, then modified the loading lever to use as a disassembly tool and I was ready to tackle the cylinder.

Oops. Too big to fit in the chuck of my metal-lathe. Bugger. Other concerns (like paying the bills) intruded and the project languished. Over the months the project was waiting patiently I started reloading .44 Colt (original.) This used a .452″ heel-base bullet in a straight-bored chamber. I got to thinking- what if I did a longer version for the walker? It would simplify things quite a bit as I could straight-bore the chamber using tools I already have… interesting, but the cylinder was still too big for my lathe.

Yesterday we were having a rather stressful morning and Linda said, “OK, just go in the shop and play.” Okey dokey, I can do that! I removed the nipples and set to boring through the cylinder and reaming the chambers to .454″-

Next I chucked the cylinder up in the lathe and turned the base around the ratchet to 3/4″- this allowed clearance for the cartridge rims. I used .44 Colt ammo I had on-hand to test this-


Of course it’s still very rough in the photo; I did clean it up before bluing!  I apologize for the lack of further in-progress pictures- I got far too involved at this point to remember to take them.

Next it was time to make the breech-plate. I grabbed a hunk of 1020 steel, bored a 3/4″ hole and cut and ground to shape. This involved relieving a 1-1/4″ circle about 3/32″ deep around the central holes so that it would sit flush with the gun’s breech, and I did this with the Dremel using sanding drums and grinding wheels. Life will be easier when I get the mill running…

Once that was fitted it was time to do the loading-port in the frame. Once again the Dremel with sanding drums and grinding wheels went to work… After I had cut the frame I made a matching cut in the breech-plate, a little bluing and that was done.

Last thing to do was to make a firing-pin. I inserted a Sharpy-marker in the chamber and marked where the firing-pin needed to be, then bored a 5/64″ hole at an angle to put the end of the pin under the hammer. I then bored this hole from the hammer-end to 3/16″- not quite through- and found a suitable spring to fit the hole. I had a firing-pin that I’d turned for another project that didn’t work, and it was a perfect fit! I staked this in to retain it and the gun was basically finished. OK, I still need a front-sight, and I am planning on permanently mounting the breech-plate, but the gun is functional.  I used primed .44 Colt brass and it went ‘Pop!’ so it’s all good.

Like a .357 shooting .38 special, while the gun is designed for a longer cartridge .44 Colt will work just fine- better, even as the cylinder is bored straight-through. So what is the guns actual cartridge? A wildcat based on .445 Supermag that uses a 200gr. Heel-base bullet loaded over the equivalent of 50 grains of black powder. The new cartridge will be called .44-50/200 Walker. I still need to obtain brass and dies, but until then I can shoot .44 Colt.

The new cartridge should, with the correct smokeless load, drive it’s 200gr. bullet at 1150+ fps. from this gun’s 3-1/2″ barrel, yielding in the neighborhood of 600ft/lbs of energy at the muzzle.

So, here is the gun, if not finished at least in it’s final form- shown with a custom Richards-Mason conversion for scale:

Now I just have to wait for the brass and dies…


Michael Tinker Pearce, 01 Feb. 2018

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