.22's I wouldn't worry about too much, its takes 100s of thousands of rounds to wear out a .22 barrel, though if you rapid fire it every time you shoot it for extended shooting sessions, I would imagine that you might become one of hte few people to ever wear one out.


There is some porportion to the the amount of powder you burn and how fast the barrel wears out. Small caliber large cased magnums tend to burn out barrels really fast, while mild middle of the road .308/30-06 barrels last a lot longer.