breech plug

[chuck-ia]

I finally got the breech plug in my green mountain 50 cal. barrel the other day, course I missed the flat that I wanted, I wanted to keep the makers name and cal. on the bottom flat. The plug measures under 1/2" now, more important to me is the number of threads. I had to file off approx 1 thread off the bottom of plug because the threads in the barrel did not go all the way to the shoulder, (hope you follow me) I ended up with between 4 and 5 threads, is this going to be safe? would appreciate your oppinions. flinch

 

[rich pierce]

Is this a 5/8 x 18 or what?
I think you'll be fine. I do not hesitate to shorten a plug by one thread. They are generally longer now than on originals and the threads are finer and stronger too than on most early American guns.

 

[chuck-ia]

it is a 5/8 by 18, thanks, flinch

 

[paulvallandigham]

As long as the face of the breech plug butts up against the rifled bore, and there is no gap between the breech plug face and the bore, you will be okay. If you do have a gap, you might fit a slug, or spacer made to fit and fillthe gap between the face of the plug and the bore. I had to do just that with a semi-custom made gun I converted from percussion to flint, and found that the maker had not fitted the barrel to the plug, leaving a gap that was collecting powder residue and rusting out the back of the barrel no matter how much flushing and soap and water I put down that gun when I cleaned it.