FYI, Arms Unlimited is up to their shenanigans again. Prior to receiving my upper, someone had posted a two start out of five star review of this upper. There were valid points, but I think it was overly critical. Well, that review is now gone and there's a new review that's five star. While there's no good reason to ever manipulate such a rating system, Arms Unlimited really has no need to do so. Many of their offerings are unique and speak for themselves. I guess some people don't feel that they're not doing their job unless they're pulling one over on someone else.

On a more positive note, I was able to buy a factory Colt SBR lower half to mate to this upper.