The innovative SHRIKE 5.56 upper receiver is designed to fit any MIL-SPEC quality AR-15/M16/M4-type lower receiver and features a dual-feed system, allowing users to configure the SHRIKE 5.56 from ...

HaveBlue's custom creation (Opens in a new window) is a .22-caliber pistol, formed from a 3D-printed AR-15 (M16) lower receiver, and a normal, commercial upper.

However, the T65 is hardly a clean-slate design, practically copying the M16 design in the lower receiver and heavily emulating other elements in the upper receiver. The primary difference between ...

However, the T65 is hardly a clean-slate design, practically copying the M16 design in the lower receiver and heavily emulating other elements in the upper receiver. The primary difference between ...

Following the EPR's release, engineering tests of M4/M16 rifles firing the M855A1 showed ... the EPM into the magazine well of a carbine's lower receiver that positions rounds for feeding.