machining cap and ball cylinder?


January 8, 2013, 01:17 AM
id like to convert a pre-existing cap and ball cylinder to take cartridges.. what i would like to do, is have the chambers bored through, and the back side where the nipples are at machined off.. just like the cylinders in the kirst converters

id like to do this as opposed to buying a pre-made cylinder because all the pre-made cylinders are 45 colt 5 shot... by boring a pre existing cylinder out i can fire .44 colt with a heeled bullet... reason would be for historical accuracy as this is what these revolvers were typically converted to fire

so my question is... how much work is actually involved, and would it be possible... and probably less of a headache to find someone that can do it for me at a price?

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January 8, 2013, 12:07 PM
Well, if you turn the nipple section of the cylinder off, you would still have to replace it with a backing plate holding the new firing pin or pins like Krist does.

Otherwise, the cylinder would be much too short to fire cartridges from it, because there would be 1/2" or so excess headspace.

What model gun are you asking about??


January 8, 2013, 01:12 PM
its an 1860 army.. and my intent was to use a kirst backing plate... though as i think about it... that might not be very historically accurate.. didnt the backing plate of the original conversions have a hole through the backing plate with a hammer mounted firing pin?

January 8, 2013, 03:21 PM
It would probably cost less in terms of time if you had Kirst or someone make a cylinder in the caliber you want. Someone even does .44 Remington CF.

January 8, 2013, 03:58 PM
This is one of my "great white buffalo" projects. There is a lot of good info on the internet, including pictures, from folks who have installed a conversion cylinder as well as straight up conversions of cap 'n' ball revos.

Least expense is to buy a replica "conversion" imported from Italy as a firearm. Second least expense is to convert using a conversion cylinder. Having a gunsmith make a conversion would be very expensive, and the 'smith would need to "manufacture" a firearm in the process. John Gren in WA used to do this and I actually sent a gun for conversion which he never got to before he got really sick. I actually got the gun back :) but was out my deposit :(

The conversion cylinder in a Colt style revo really needs some additional work to the gun to match a period conversion, such as a loading cutout in the frame. So you don't necessarily bypass all machine work with one of those.

Anvil Enterprises used to sell plans to convert an 1851 Navy; these could be adapted to any similar open top Colt C & B pretty easy. I do not believe they are still around, but I'm not sure and maybe there are other similar plans out there.

There was an excellent book on revo cartridge conversions a while back (R Bruce McDowell ??) that is now super expensive. It had a lot of good detail on the real historical conversions, and explained the whys and whynots of the originals. It also showcased modern replicas of conversions on various other style revos, such as Rogers & Spencer replicas.

Back in the day these conversions were fairly common and often poorly executed by blacksmiths.

To get into the meat of your original question, you could perform all the steps just like they did back then. Lots of these were done by people with simpler tools than available today, but you really need a lathe and a mill.

The 44 cylinder Colt (or repo) has way too little meat to make a safe conversion. I have handled many of the originals and almost all have cracked cylinder walls and even little open windows where the charge holes blew thru the outher cylinder wall. Check out how the cylinder is rebated (smaller diameter in back). Look from the front; the nipple holes are not center line with the part you load powder and ball, and the two parts of the hole are different inside diameter. There is a real dimensional problem and these really require a new cylinder and frame modification.

The 36 cal Colts are much better to work with due to the lack of cylinder rebate and stepped frame. A conversion on the original cylinder can leave the locking notches in the cylinder alone.

The cylinders are also short once you turn off the part where the nipples screw in. The breech ring mentioned in a previous post fills the space where you remove the back part of the cylinder (not removed all the way to the center, just down to the part where the ratchets are located). This limits cartridge OAL.

The replicas are made of softer steel than modern cartridge guns. You need to be really careful and keep this in mind. On the other hand, the originals were iron. I would make my breech ring from something like 4140 or better and also sleeve the barrel and charge holes with similar. I'd also go with a weaker cartridge (32 or 38 S&W maybe) and load a BP substitute.

Lots of problems, but a really meaty problem and I think a great project. If you do not have access to a lathe (and know how to run it) you will have a low probability of any success. But don't be too discouraged, you can learn the necessary skills if you are determined. This is a project that you can accomplish.

January 8, 2013, 08:18 PM
i thought about the metalurgy aspect of it.. however, even the softer metals used in todays replicas is better than the metals used in the originals, and using black powder loads within specs of the original cartridges would be fairly safe...

but i already looked at the front of the cylinder and imagined it slightly narrower like the rear section of the cylinder... and the cylinder walls in the rear would have to be incredibly thin... this concerned me, but it does seem that if the loads are black powder loads loaded to the specs of the original cartridges, the better metallurgy should make up for it a bit

but youre right.. converting an 1861 navy to 38 special would probably be better, easier, and safer.. but it would be nice to take one of these fairly accurate reproductions and perform a fairly historically accurate conversion to 44 colt on it, but these revolvers are cheap, i guess after i move, i was planning to get a mill and lathe anyway... i could convert one of each, not like these are expensive revolvers

all that being said.. perhaps i should purchase a richard masons style conversion from cimarron, they offer one in 44 colt, and in 44 special too.. i guess ill buy one of these in .44 special for the bulk of my shooting, and make the 44-colt out of an 1860 army for the sake of being more traditional

January 8, 2013, 08:28 PM
First thing to do is slug your .44 barrel and see if it's a .45.


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