AR Question: Barrel

[Trigger]

I've noticed that many AR-15/M-16's have a step off on the barrels. THe thickness of the barrel is thick coming out of the handguard then narrows, then get thick again before the muzzle brake or flash suppressor. Why is that?

 

[usp_fan]

The step in the barrel is to allow the mounting of a grenade launcher (M203) to the short barreled carbines (M4). The step serves no function on civilian guns except to look cool, loose a little weight, or serve as a mounting point for a 37mm flare launcher.

On A2 profile barrels (20" narrow under the handguards) the step isn't required because the barrel is long enough where it is narrow to allow mounting the M203 by removing the lower handguard. On the short barrels, the forward clamp of the M203 mounts forward of the front sight. Thus the step.

HTH,

--usp_fan

 

[Trigger]

Thanks. Thats what I thought. I just had my AR worked over and thought the same profile all the way through just looked better than the step.