That is some interesting reading. The only point I disagree with him is why lead deposits would build up near the muzzle of a 22 but not further back in the bore. He theorizes that the molten lead on the base of the bullet has cooled by the time it reaches this point along the bore, and at that point cools enough to coat the bore as a solid material. I disagree. A 22LR bullet is a lubricated lead bullet, and as such, the lube is smearing off as the bullet travels down the bore. Since there are no grooves on the bullet, like there are on a cast lead bullet, the 22LR bullet doesn't have enough lube to make the full trip down the bore before it runs out of lube. I think this is what you are seeing with these lead deposits near the muzzle. That's the point where the lube is running out.
