[Roundsworth]

Calvin, as Austin said, your extractor may be an issue. My 1877 lifter did not have a serialized extractor, which may or may not indicate a replacement. I used Dykem Blue and checked the interference between the breech face and extractor. Needless to say, I had to carefully file many thousandths off the extractor before I could get the action to close properly. THEN, I worked with shims. I bought a little $5.00 feeler gage from my local hardware store and cut a piece from the .004" gage to bring the barrels back 'on face'. I know you want something more permanent, but the shim does work for me. Good luck!