Frankenstein 1860 Conversion

Thinking of a project involving conversion of a C&B 1860 Army into a cartridge .32-20. Cartridge conversions to .45 LC are established. Will involve the basic conversion of the C&B into cartridge (Kirst Konverter) and then reaming a barrel to accept a .32 (.312") barrel liner and creating chamber inserts into the .45 LC cylinder or modifying a .44 C&B cylinder to accept inserts in .32-20. Looked originally at using an 1851 Navy but those cylinders aren't long enough. 1860 cylinder is. I already have a .36 Navy barrel so will use that as the donor barrel to reline to make a Navy look on a Army frame. Larger grip is fine and barrel length will probably end up 5.5 to 6 inches.

Does anyone see anything inherently wrong with the thought process?

It has been a while since I had both an 1851 Navy and an 1860 Army apart at the same time. I see two maybe problems: 1. Will the Navy barrel fit on the arbor of the 1860? and 2. Mounting pin distance and barrel centerline from the arbor of the navy barrel when mounted on an 1860.

It would not be good if the barrel and cylinder don't line up.

Good Luck,

Robert

Barrel fit on the two pins at front of frame has been checked and is tight and exterior contours fit as well. As for the cylinder and bore alignment I'm thinking that if they aren't "naturally" concentric that the chamber inserts can be reamed a bit off center to compensate before they are fixed in place. barrel fit on cylinder pin is tight and wedge hole appears appropriate also.

Doing a 51 Navy in 22 LR for a customer now. He found a cylinder that was designed for the 22. At the point of making an extractor now. Made a barrel liner from a cut off rifle barrel.

Howell Arms and Kirst both make conversions for 1851s to .22.

Project is moving along. Have a .32-20 pistol barrel that I might turn down but also have some .32-20 barrel liner on order. Have drill bit and reamers on order to ream 1851 barrel for liner. Have a couple of different round bars of 4140 for chamber inserts plus the chamber reamer and Go and No-Go gauges. Have Kirst Konverter in .45 LC. Also have a .44 C&B cylinder that I may try to line permanently and bore through, otherwise I'll make chamber inserts for the .45 LC Kirst cylinder.

Great thread, enjoying the progress

Good speed

Mike

raises question,

its known that the cartridge conversion process increases the stress on the frame, and severely shortens useful life.

If 45 colt is bad, thoughts on 32-20? and then consider MODERN factory is all the Hi Vel stuff

32-20 will all be handloads to BP pressures and velocities. Cast bullets, same as I'm running through a '73 Winchester clone.

Making progress, albeit slowly.

Cut Barrel and Liner
Attachment 293219
Bored Barrel and Turned Liner
Attachment 293220
Bored Barrel and Turned Liner, Muzzle
Attachment 293221
Barrel With Liner Inserted for fit
Attachment 293222
Chamber Insert..45 LC on bottom, .32-20 on top.
Attachment 293223
Chamber Insert with Cartridge (MFG from 7.62 Nagant Brass)
Attachment 293224

Watching something cool happening here!

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I do enjoy swapping calibers on firearms also. This one is very interesting ! Thank you for including it here.

Bolt-thrust or breech face pressure for a 45 Colt is higher than that of 32-20. The 32-20 operating pressure is marginally higher than the 45 Colt, but the area of the case head pushing against the breech is much smaller - .0.098 square inch(.354 head diameter) vs 0.181 square inch(.480 head diameter) for the 45 Colt. Multiply the area of the case head times your pressure to get breech thrust. Standard 32-20's(16000CPU) should not be a problem.

Update - sorry for the absence for a while. Got involved with a movie in Montana for 5 weeks after the first of the year and life happened... In any case had another project crop up so did a cartridge conversion to an 1851 Navy to .38 Colt and just finished nickel plating it. Set up as an early Richards type conversion without the Mason ejector addition and a bored through percussion cylinder with the Naval roll engraving.Attachment 298184

For the .32-20 project am considering modifying the plan to use a '51 Navy frame then modifying one of Pietta's 6-shot derringer cylinders (for length) for the inserts/.32-20 chamberings.

interesting projects!

"Got involved with a movie in Montana for 5 weeks after the first of the year" sounds a bit chilly.
..

They did have a cold snap that required most of the cold weather gear that I had taken along. Coldest day started at about -15 and warmed to about 0 without the wind chill. But we did have some 45 degree days too. At least the bears were still in hibernation until the day after we wrapped.

Getting back to work on this. Barrel needs the dovetail cut and front sight installed plus final forcing cone extension determined to mate with final cylinder length. All of the cylinder liners are epoxied in place and two have the chambers cut.

Have made some progress. Barrel is lined and cylinders have had inserts installed and new chambers cut. Working on final tweaks to conversion ring. Have ejector assembly ready to install.

Need to convert a hammer to have a fixed firing pin and modify the conversion ring a bit. Have dovetail front sight to install and then will zero for 25 yards or so.

Second pistol is an 1862 Pocket Police to be converted to .38 Colt. Cylinder is converted and have a conversion ring machined but still need hammer cut and loading port. Need to convert hammer to fixed firing pin.

Attachment 320504

Attachment 320505

Amazing still!
To this day those type of Colts point better than anything else for me.
Thanks for the update, 36G!


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Quote:

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Originally Posted by BunkTheory

raises question,

its known that the cartridge conversion process increases the stress on the frame, and severely shortens useful life.

If 45 colt is bad, thoughts on 32-20? and then consider MODERN factory is all the Hi Vel stuff

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There are more than a few 1860s that have been converted to 45 ACP. They operate at much higher pressure. Of course the arbor length has been corrected and basically the replica is tighten up to the way the originals were made.

Kevin

I have a Cimmaron 1872 Mason Richards conversion in 38 caliber. I load 38 Specials. The gun shoots great! Might be a better candidate to convert to 32-20?

Quote:

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Originally Posted by Rockindaddy

I have a Cimmaron 1872 Mason Richards conversion in 38 caliber. I load 38 Specials. The gun shoots great! Might be a better candidate to convert to 32-20?

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I've got a couple of the 1872 Cimarrons and I agree that they are nice. Relative cost of converting an 1872 vs. a 1860 C&B was the driving factor. A C&B cylinder is much cheaper to replace than a cartridge cylinder should a mistake occur as are barrels.

36g, I'm really interested in that 1862 Pocket Police Conversion. I've been thinking about making my Uberti 1862 PP convertible to 380 acp. Have you given that caliber conversion any thought?
It seems to me that the barrel diameter discrepency could be resolved by electroplating with a thick 0.007" hard chrome layer to reduce the bore to approximately 0.355". Diameter of the front half of the chambers could be reduced with approximately an 0.008" chrome layer to allow use of .380, 9mm, or .38Sp cast bullets with the c&b cylinder (I haven't finalised on that chrome chamber thickness yet). I was thinking the conversion ring, loading gate, and firing pin could resemble a miniaturised Kirst .45 acp ring and gate.

(I really like the Kirst .45acp conversion on my Uberti 1860 Army)

36g, on the 1862 Police conversion is it Uberti or Pietta?
How much wall thickness do you have between the chambers and the ouside wall on the cylinder aft of the rebate?