Barrel wear question

[Captk]

I recentley picked up 2 Savage 223 rifles, a model 10 and a model 112. Both have 1/9 twist barrels. I was trying different ammo to see what worked best, 55 gr FMJ (Fiocchi, Hot Shot), 69 gr (Prvi, Bitter Root valley) and some 40 gr Fiocchi. The 40 gr was noticable more accurate then the other ammo. My questions is since the 40 gr is about 3,600 FPS does that lead to faster barrel wear and shorten it's life? The other ammo ran from 2,800 fps to 3,150 fps.
Thanks, Ken

[darkker]

Wear comes primarily from two sources: Heat, and friction.
Heat can be from friction, but in this explanation from the flame-front of the powder traveling down the barrel.
The friction is the bullet in the bore. Since the powders are undoubtedly different, you can't make a straight comparison to the two types of ammo. The 40 grain bullet will have a smaller bearing surface than the other two, but have more powder behind it....
Any 223, running factory pressures and bullets, will have a VERY long life; provided you aren't dumping rapid shots routinely down the pipe.