Quote Originally Posted by brasse View Post
Call me confused??? I always thought lapping the bolt head was done to the outside surface that fits against the barrel, and not to the inner surface that the brass sits in.
OK, Hi Confused

Your lapping the lugs and the abutments to each other, why it increases the headspace. It removes material setting the bolt back away from the chamber. If the headspace was set with only one lug making contact .005", once its removed by lapping the headspace would increase the same amount or .005".

Bill