It's true, the bullet itself does very little to wear the bbl. out! Guilding metal is much softer than bbl. steel.

I once read about a guy who fired some unbelievable number of bullets through a bbl. useing compressed air instead of gun powder, and he STILL didn't wear out the bbl.!!! He did it to study bbl. wear.

I forget the number but i think it was something like 100,000 bullets, and then pretty much gave up!!

Bbl. wear comes mostly from generated heat in the throat area of the bbl..

Drilling Man