I've got a Lee "SMLE" 185gr. gas check mold that I polished out to .315. It works very well with my big-throated Arg. Mauser. But now is too big for even .311 gas checks.
I'm shooting it checkless with mouse loads (5-6 grains of Red Dot). Lotsa fun.
It gives me pretty good groups without gas checks. But I'm thinking that if I make it a truly a plain-based mold by taking out the gas check groove, it will shoot even better.
Question: What's the best way to open the base? And would it make much difference?
Any guidance appreciated.