[stagpanther]

I pull barrels quite a bit off of well-used rifles, I've found that the area around the chamber and the extension where it fits into the receiver is a cauldron of high-pressure heated gas which mixes with combustion residue and residual cleaning solvent--it's going to find a way into any joint. The other thing about lapping that I became nervous about it was that I was unsure of how it might affect headspacing and lug lock-ups--I suspect that even minute depth changes could make a difference. The extension pin slot may or may not also be affected--I had a barrel once that absolutely refused to work with any bolt and I eventually figured out the extension pin was slightly out of clock with the gas port and lugs. I'm not saying it's a bad thing you shouldn't do--but I suspect that it's not as straightforward as blueprinting a bolt action receiver. I'd like to hear from an industry expert to weigh in on this. My opinion about any receiver to barrel mating that involves shims is that is inherently going to cause problems sooner or later--always has on any rifle I've used them on.