Aero Precision Atlas R-ONE Upper Assembly, 5.56mm NATO, 16.7" Barrel (Pinned & Welded)
This Aero Precision Atlas R-ONE upper assembly is built around a 5.56mm NATO barrel with an ATLAS R-ONE M-LOK handguard and a full-length top Picatinny rail. It is ready to mount on a compatible lower receiver and uses a direct impingement operating system.
This upper includes a bolt carrier group and charging handle. A gas block and gas tube are needed to complete the upper.