Ok, here's the deal. I picked up a sweet 1895 1\2 octagon 1\2 round barrel in 45-70 for my Darcy falling block project.
It has square threads of course. I measured the thread major and it comes out to .780ish.
Converting that I get 25\32 or 19.84mm.
My question is for those who have cut threads in a receiver for these barrels. What tap did you use? Where did they come from?
I'm having trouble locating something.
I have considered turning the treads off on my lathe and cutting my own, but losing that much of a safety factor makes me a little nervous. I'm kind of attached to my face!
Anyway, if someone can help point me in the right direction I would appreciate it.