300 blk upper
Overall very pleased. It is stout, reliable and all around great addition to my 5.56 upper I got from your company. My only 2 complaints is the take down hole on the upper is a little small and I have to really hammer the pin in the lower and then the crush washer on the muzzle was warped. I replaced my standard a2 birdcage with a surefire warcomp and the crush washer would not come off I ended up having to use a dremmel to cut the crush washer off so I could mount the warcomp