Bear Creek Arsenal BC-15 .300 BLK Upper Receiver - AR-15 Complete Upper - 7.5"

A compact .300 BLK upper ready to drop onto any mil-spec AR-15 lower. The Bear Creek Arsenal BC-15 .300 BLK Complete Upper ships with a BCG and charging handle already installed, built around a 7.5-inch 4150 Chrome Moly Vanadium barrel on a pistol-length gas system — the configuration that keeps .300 BLK pistol builds running reliably with both supersonic and subsonic loads.

The Bear Creek Arsenal BC-15 .300 BLK Complete Upper is a mil-spec AR-15 complete upper assembly with bolt carrier group and charging handle included, featuring a 7.5-inch 4150 CMV parkerized barrel on a pistol-length gas system with a 1:8 twist and M-LOK split rail handguard.

Four specs define this upper's role in a compact .300 BLK build. The 7.5-inch barrel maximizes maneuverability for SBR and pistol configurations while remaining fully compatible with the .300 BLK cartridge's design intent — a round engineered to perform effectively from short barrels at both supersonic and subsonic velocities. The pistol-length gas system provides the correct dwell time for reliable cycling in a 7.5-inch .300 BLK barrel, where a longer gas system would generate insufficient pressure for consistent operation. A 1:8 twist rate stabilizes the full spectrum of .300 BLK projectile weights — from light supersonic loads to heavy 200-plus-grain subsonic bullets — making this upper versatile across the entire .300 BLK ammunition range. The black nitride spiral flash hider manages the muzzle signature of a short .300 BLK barrel, where the larger powder charge and shorter dwell time produce a more prominent flash than longer configurations.

Compatible with mil-spec AR-15 lower receivers. Includes BCG and charging handle. M-LOK split rail handguard.

4150 Chrome Moly Vanadium barrel, parkerized. Black nitride spiral flash hider. Pistol-length gas system. 1:8 twist.

Built for .300 BLK AR pistol and SBR builds requiring a complete, BCG-ready upper at 7.5 inches for maximum compactness.

By Bear Creek Arsenal. BCG and charging handle included. Standard Bear Creek Arsenal warranty applies.