Don't install another ar-15 barrel without it! - Wheeler Engineering Delta AR Upper/Pic Rail Vise Block

I wanted to swap out the barrel of a BCA buffer less 9mm upper, which was torqued down HARD. It would not fit in my old AR-15 vise block, because the upper is thicker than standard AR. This device uses the receiver's takedown lugs for indexing / securing the receiver. So it doesn't matter how the upper is shaped / sized, as long as the surface that mates with the lower is mil-spec. Using this fixture, the Wheeler 30 mm crows foot barrel nut wrench, and a 1/2" drive torque wrench, I had the old barrel removed literally five minutes after UPS dropped off the package.