Proving that every once and awhile, the Government can do something right, the GUNNER's profile from the extension to the gas block mimics that delicious taper. From there, common sense takes over and the GUNNER moves to a .625" gas block journal and our famed pencil profile out front. Removing the weight from the front of the barrel ensures maximum versatility and keeps material to the rear to maximize heat resistance and mitigate whip.
I am building a retro style M161A rifle. Other than a 1:8 twist and not the OEM 1:2 twist, indistinguishable from OEM from the outside. I prefer Nitride in the bore as it's a teeny tiny bit more accurate.