It's also perfectly legal on a pistol lower, no? If it were ONLY 14.5" on a pistol lower, yes. But at 16", it becomes a rifle barrel. Then you could get yourself into a pickle having both pistol and rifle listed at lower assemblies which are the actual firearm by virtue of serial number b...

I'm new here and just finished my first AR. Shadow Ops lower w/ Rainier & BCM upper parts.