Originally Posted By BeetleBailey:
I guess my most major concern is wearing out the rifling rapidly since the bore is tighter and using heavier bullets.
They all use a 0.224" bore and most match ammo is heavier than SS109, so...
The chamber itself is tighter and a match barrel has a limited service life before accuracy starts to degrade. That life is measured in the number of rounds fired through it and it doesn't matter if those rounds are a bunch of cheap milsurp ammo in a few afternoons or handloaded match ammo over the course of a few years. Looking at it from that point of view it would obviously be stupid to waste the life of a good match barrel with just going out and plinking. If you want something for a bunch of rapid fire shooting you should get something chrome lined from Bushmaster.
Does 62 gr. or M855 or ss109 or whatever use more/denser powder to move the heavier bullet better?
Military ammo, both M855 and M193, is loaded fairly hot, but even then we're still talking about 5.56mm. The really hot stuff like .22-250 or those new .223WSSM will have issues with throat erosion.