I’m loading the 124 gr TCFP Matchwinners, and I’ve run into a problem. My normal case mouth belling has worked for over 30,000 RMR round-nosed bullets, but the MWs are giving me fits. My normal mouth bell seems too tight for these bullets, and they get cocked (off center) in the case during seating. This results in the cases getting bulged and they are rejected by the case gage. I tried increasing the mouth bell a few thousandths, with the result that about half the bullets fall into the case too far. I can’t believe a couple of thousandths of an inch could make such a difference! It seems like the MWs have a sharper corner on the base of the bullet that is less forgiving than that on the RNs, but that’s just a guess.
FWIW, I’m using a flat-nosed stem in the seating die, since the bullets are flat-nosed and I don’t want to engrave them during seating. Should I revert to the radiused stem for the round-nosed bullets?
Looking for advice and suggestions. Has anyone else run into this problem?
.
