Got a new AR 15 today. An Armalite with a 16" barrel and mid length quad rail hand guards. My older AR is an RRA with carbine length hand guards. I'm curious, what do you all prefer in regards to the rifles having either carbine, mid or rifle length hand guards? I heard somewhere before the longer the gas tube, the better the function and fewer the problems. Any truth to that or is it rubbish? I think I'm really digging the mid quad rail over my carbine length on my Rock River.