Thread: Lapping barrels

My understanding of the lead lapping process is it does polish, of course, but polishing can be achieved in many other ways. The unique thing the lead lapping does is to make the bore and rifling uniform throughout. It is intended to turn a cone into a cylinder.

So if, as is common, your muzzle-end is a bit shot out, that's only a problem because it widens out from the rest of the barrel. You can have a wide long throat and the rifle may still shoot well, but a widened muzzle end is never good. The lead lap is cast at the muzzle and will make your bore (lands and grooves) uniform 'shot out' depth throughout the barrel. It will make sure all the barrel is like the muzzle, because so long as ALL the barrel is uniformly 'shot out diameter' there's no problem.

It's really a procedure for very pitted / shot out milsurp barrels, not for improving fine target barrels. I have a few .303 barrels awaiting their day of resurrection that way.