MEAN ARMS Bearing Delay 9mm Luger Complete Upper Receiver

The Bearing Delay Upper Receiver is a complete upper receiver system ready to be paired with the AR lower receiver of your choice. Available in five barrel lengths: 4.5, 7.5, 11, 14.5 and 16 inches, all threaded for a 1/2-28 muzzle device. No 9mm-specific buffer is required; the system works with standard AR-15 buffers. At the heart of the Bearing Delay Upper Receiver sits the unique ball bearing bolt carrier group (BCG). The ball bearings interface with the barrel extension to provide lockup in battery and the delay after firing. The system can be tuned by swapping the Lifters, and the bolt face includes a center ejector. The firing pin passes through the ejector. Each Bearing Delay Upper Receiver includes two Lifters. Also included with the Bearing Delay Upper Receiver are two EndoMags, PMAGs not included. The MA Upper Receiver is a slick side billet machined aluminum upper receiver with a matching MA Handguard, MA Charging Handle, and MA Muzzle Device.