You're going to also want to check that the breech ring is not being "Sandwiched" between the feed ramp and the barrel face. Even if you follow the dimensions exactly, sometimes the breech ring will push back against the feed ramp and push a bur up.
Also, the breech ring can benefit from having the lug corners polished where the brass will pass by during extraction/ejection. They can scratch the brass up pretty good.
Lastly, ensure that the actions extraction cam angles where the bolt handle contacts is not being "Peened" down into the raceway. After many cycling metal can get displaced and pushed down into the raceway contacting the bolt body.
Mark