BCM/Rosco/SOLGW Upper Receiver 12.5" – 5.56 NATO, 1:7 Twist
This AR-15 upper receiver assembly is chambered in 5.56mm NATO and configured with a 12.5" barrel and a SOLGW M76 free-float M-LOK handguard. The upper features a full-length Picatinny top rail, forward assist, and ejection port cover, with a muzzle device installed.
Barrel markings indicate 5.56 NATO with a 1:7 twist and 416R steel, and the muzzle is marked 1/2x28. No charging handle or bolt carrier group is provided.