Just acquired a new to me 1871 38-55 Target model. Put 20 rounds of Precision Cartridge ammo downrange with poor results. Shots patterned rather than grouped, had a half dozen tumblers as well. I have slugged the bore and it measures .381". The Precision ammo uses .377" bullets so that would account for the poor accuracy, I'm sure. Next step was to load some Cast Precision .380" s in the thinner walled Starline brass. Loaded rounds would chamber, but not at all easily. at this point it would seem that chamber reaming is in order. My question is, which reamer? 4D lists three, .395", .398" and a .400". I made a chamber cast and it measures right at .395-6". So, am I correct to assume that the .400" reamer would be the correct one to use? Also, will standard 38-55 reloading dies work with the reamed chamber? The dies I have on hand are Lee. Any and all help and input will be greatly appreciated.
Thanks!