Worried about bolster

[jimikinz]

Hello,

I just installed my first powder drum...and its got me a bit worried. I have a 7/8" .50 barrel, and I installed a 1/2 drum wtih 5/16x24 threads. Now that it is installed, it seats flush, but its ever-so slightly off-center on the barrel flat - maybe a 64th or so low?

I still need to remove it and shape the inside of the threads to follow the inside diamter of the barrel correct? Given that is off, the effect will be that the inside edge of the threaded instert of the drum will be holding with a thread or so fewer on the bottom than on the top...at least that what it seems to me.

Is this a safety concern?

 

[hoochiepapa]

I would say, nope. There's quite a bit of meat at that end of the barrel. and with bp pressures, you should be okay. Be sure you get that inside barrel portion flush, otherwise your patches will always hang up.
Still waiting for your parts.

 

[Zonie]

With a percussion gun, the nipple drum must be resting against the lock when the barrel is installed.

This is important because if the drum is not contacting the lock plate, the entire blow of the hammer will be directed thru the threads. This can result in breaking the drum at the threads.

If your drum is slightly off center relative to the barrel flat it should be of no concern provided the drum is supported by the lock.

Yes, you must remove the drum threads that will be sticking out inside the bore. Not removing them will lead to no end of problems.
Just do some careful measuring before trimming the threads off and try to keep as many threads as is possible without the end protruding into the bore.

 

[Bill Hall]

This is important because if the drum is not contacting the lock plate, the entire blow of the hammer will be directed thru the threads. This can result in breaking the drum at the threads.

I never thought of that before, but makes perfect sense. Something to pay attention to when building, or buying a rifle with a drum. Good tip Zonie, thanks. :thumbsup:

 

[jimikinz]

OK...thanks guys. That makes me feel better. Turns out that with it low, it made it hit the lock plate ( I had to file the plate a bit) more that I intended, so thats good!

Jim