Works perfectly fine but a small portion of the threading was flattened, looked like something pressed up against it. Not a big deal though I suppose because I was still able to screw on the zenitco muzzle brake. Just had to put some elbow grease when spinning that part of the thread.
It functions the way it should. However, the black finish literally wiped off the first time I cleaned my rifle after installing this FSB. I was using MPro 7 to clean it. Not a big deal for me since I was having the rifle re-finished after conversion anyway, but people should be aware that this is a possibility.