Blackout Defense Quantum Mark 2 AR15 Stripped Upper Receiver

The Quantum Mark 2 upper receiver is machined from Aerospace Grade Aluminum with enhanced walls for greater rigidity and structural integrity - all while keeping a low profile. It features two anti-rotation holes that align precisely with their handguard. If you're not using their handguard, simply install your own as you normally would. The anti-rotation holes will simply not be used. The dust cover often goes unnoticed in an AR-15. Not to us. The dust cover is fully contained within the upper receiver. They don't rely on a C-clip to keep everything in place. Instead, the dust cover hinge pin is held in place by the barrel nut, ensuring nothing comes loose during operation. One thing you'll notice upon installing the dust cover, it will be tight to close. Due to the variation of dust cover manufacturers and their loose tolerances, we've machined a very thin locking groove in the upper receiver. This allows the ball detent of the dust cover to "cut" its own channel in the upper receive