The Sig 516 was my second AR15 purchase and I think it is an excellent AR15. I have fired hundreds of rounds through it and never had a misfire. This is a gas piston operating system and requires less cleaning than a direct impingement rifle. Popular belief is, if you want accuracy, do not buy a gas piston operating system AR15. I have four AR15s and three are piston operating systems. My Sig is quite accurate at 200 yards with the Hawke scope. I do not use target grade ammo because of price, and I am not shooting for one inch or less MOA(measurement of a group of shots). As long as I can hit four and six inch steel at two hundred yards, I think the AR15 is very accurate. The only problem with Piston AR15s is that they are more expensive than the direct impingement rifles. I posted two You Tube videos that are interesting and entertaining.