PP with 400 or 600 grit paper?

[Bent Ramrod]

From my experience, fire lapping doesn't remove deep pits, but it does knock the sharp edges off them and reduces their tendency to collect lead and damage subsequent boolits. The barrel will start off speckled and dark with deep pits and finish with shiny areas and the pitting more isolated and somewhat shallower.

Clover 320 is my "go-to" size. With the boolit coated and embedded with this material and seated in the throats with tweezers and dowel, a single case is reloaded and fired, with appropriate cleaning in between. I have fired 40 or 50 shots in a morning, with cleaning every five, checking for improvement with my "best" previous load, and come back several times to do the same thing until I figured that the barrel was as good as it was going to get.

I'd like to see somebody turn a .30 caliber barrel into an 8mm or .35 barrel by fire lapping. Not by sitting and watching, just by checking back every five years or so.

[Good Cheer]

The barrel I'm working with was fired by the previous owner using mil surplus soft nickel jacketed ammo. The bore was matte silver. When cleaned with bore solvent the nickel disappeared. And then iron grit fell out of the bore. Yeah, that bad. That was a couple of years ago when I embarked upon a polishing followed by paper patched Clover program and produced remarkable improvement in surface. And the rifling in front of the chamber developed a groove diameter that measured 0.008" larger than the inside of a well annealed and fired case mouth. That is in part by design because the nickel jacketed military ammo was designed to bump up on the backside to fill the grooves. But it has been enlarged by erosion, corrosion and now abrasion. So now I'm back at it and have been taking it out more today. If it "improves" enough to be a shooter, cool.