Tags: Weapon.
The AR-57 also known as the AR Five-seven is an upper receiver for the AR-15/M16 rifle lower receiver firing FN 5.7×28mm rounds from standard FN P90 magazines. It was designed by Rhineland Arms Inc and is currently produced by AeroPrecision Inc of Tacoma Washington USA. The AR-57 PDW Upper is a new design on an AR15/M16 platform blending the AR15/M16 lower with a lightweight monolithic upper receiver system chambered in FN 5.7×28mm.