Mine is a standard 5/8 fine thread.
I put a standard fine thread bolt in there sometimes when I clean.
Busta, wouldn't the plug need a shoulder, like the original, and unlike the Knight, to "bottom out on" when tightened ?
The female threads in the barrel aren't cut all the way to the shoulder where the rifling starts, and that shoulder is quite
narrow, doesn't look like that would make a positive stop, or am I missing something?
Are breach plugs hardened?
An improperly hardened/tempered plug sounds dangerous. If the plug needs to be higher strength than mild steel,
how about an annealed or normalized alloy like 4140, are there any competent gunsmiths here that can answer this ?
I would like to have a BH plug made for my Sidekick, I've been waiting for some one to post a plan for making one (hint)
I would like it to be patterned after an existing design that works well, and specs out primer pocket diameter and length, flash hole size,
and how to measure for proper fit when closed on primer so I can have machining done only once.