I've also considered fire lapping though it seems to affect the throat area more than the rest of the bore. I don't know at this point if accuracy is lost more to the roughness of the throat or to its being lenghtened by erosion. The bullets I fired were both 250 grs, seated as far out as possible. Setting the barrel back is complicated by the key through the forearm.and also by lettering around the barrel shank. Hmmm.

Bill Ferguson