I have a mk 1 Webley, shaved to .45acp. The cylinder throats measure .448/.449".
4 gr of unique under a 250 gr soft .452 bullet is starting to keyhole. 4 1/2 gr shoots a little better, but I don't want to push this old girl too hard. The rifling is good. I haven't slugged it yet, but I can't get a .452 bullet into the muzzle or past the forcing cone.
I got a 29/64 reamer today, but it measures almost .454". Is that too much? I don't want to spend the money on Brownells, I had hoped to get away with this chucking reamer I ordered online.
Thoughts?