Drum Placement

[Pete G.]

I realize that most on this board think the proper place for a drum is in the trash (or maybe in a band), but I have a build for a client who wants caps. Looks like if the drum were placed just forward of the breech plug, then the threads of the drum will foul the plug. This is a fairly thin wall barrel, so I hesitate to trim the threaded end of the drum shorter, but this looks like what I might have to do. How many threads should be engaged to be safe? Incidentally this is built to look like a flint gun converted to percussion, so I'm sort of stuck with the drum design. I don't think I'll do another of these because I don't like it, but for now its what I've got.

[northmn]

I have safely put drums on 13/16 45's with no ill effects or disasters.  they stayed in place and withstood some pretty heavy loads.  There are original drums in rifles today that have not blown out.  The best for a thin walled small barrel is a 5/16X24 NF threaded drum.  Make sure you get the correct drill bit for the thread size and do not torque it so that you damage threads.  If you have to, back it off to have the nipple align with the hammer and solder the thing in place where it does not show.  Also make sure the lock bolster supports the drum, even if you have to shim it.  These two steps make for a safe installation.  Many like to install the drum ahead of the breech plug and then file off anything that sticks out on the inside.  Contrary to what some state I saw a 1" 54 shot with a drum and nipple configuration in which the nipple blew out and the drum stayed.  Like anything if installed wrong they do not work.

DP

[Dphariss]

I realize that most on this board think the proper place for a drum is in the trash (or maybe in a band), but I have a build for a client who wants caps. Looks like if the drum were placed just forward of the breech plug, then the threads of the drum will foul the plug. This is a fairly thin wall barrel, so I hesitate to trim the threaded end of the drum shorter, but this looks like what I might have to do. How many threads should be engaged to be safe? Incidentally this is built to look like a flint gun converted to percussion, so I'm sort of stuck with the drum design. I don't think I'll do another of these because I don't like it, but for now its what I've got.

Use a patent breech or Allens drum look alike breech if you just have to have this look. Its all about safety. 
The drum and nipple is by far the weakest and most prone to failure and misfires of all the percussion systems. Back in the day there was some justification for using them. There is no valid reason today.
Once you make the thing yoiu are legally liable for life.
Dan