Both. Fast twist barrels like mine wear very quickly, so I don't waste my barrel with surplus stuff. My AR only gets shot for load development, practice, and competition...no plinking. I coudn't afford to shoot factory made match grade ammo for practice and a match or two every month...I reload my own match grade for 1/3 the cost. If I had another AR and I was jsut plinking, however, the surplus would win out.