CMMG Zeroed Picatinny End Cap Features The CMMG Zeroed Picatinny End Cap is machined from 6061 aluminum giving it the strength needed to serve as a structural rear cap on an AR-15 lower receiver without relying on a traditional buffer tube. By eliminating the buffer tube requirement the end cap allows .22 LR builds to run a more compact and lightweight rear end since a rimfire conversion does not need the same buffer and spring system as a centerfire host. This design is part of CMMG s broader Zeroed lineup of parts built specifically to support dedicated rimfire AR-15 platforms. The Picatinny interface on the cap allows for the attachment of compatible accessories at the rear of the receiver. Because the end cap closes off the back of the lower receiver it keeps debris and moisture out of the internal components protecting the trigger group and other internals from the elements during field use. The aluminum construction keeps the part lightweight which matters on a rimfire build where reduced weight is often a primary goal. Builders converting an AR-15 lower to a dedicated .22 LR configuration will find this part a necessary piece for completing the rear of the receiver. The CMMG Zeroed Picatinny End Cap suits AR-15 builders working specifically with CMMG s .22 LR conversion components. CMMG Zeroed Picatinny End Cap Specifications Manufacturer: CMMG Model: Zeroed Picatinny End Cap Compatible Hosts: AR-15 .22 LR Material: 6061 Aluminum Caliber: .22 LR Available At: GrabAGun