Tried to use search but for some reason it doesnt work on my droid phone. My question is this, is it hard/ expensive to find & shoot good reliable ammo in 1/7 twist barrels? Im looking at buying a good AR, probably BCM, but was reading cmmg website & they say certain ammo will void their warranty. Not looking to get flamed here, just trying to get the best most reliable way to plink & defend the home. Thanks.