ive been thinkin about building a 223 ar pistol an i have a 16'' A3 upper an im thinking about just cuttin the barrel off an rethreading it an all..is there a diffrence in the gas system from a 16'' an a 10.5?? or any other problems with that??
Normally the pistol AR uses a shorter gas system. It is even shorter than the carbine system. I am sure the carbine system could be made to work with the shorter dwell time post gas port.
The gas port would have to opened up. On a 16" barrel your gas port should be about 0.063" with CAR gas sys. On a 10.5" you'll need about a 0.093" port.