Bear Creek Arsenal BC-15 .300 BLK Upper Receiver - AR-15 Complete Upper - 10.5"

The Bear Creek Arsenal BC-15 .300 BLK Complete Upper at 10.5 inches ships with a BCG and charging handle installed, built around a heavy 4150 Chrome Moly Vanadium parkerized barrel on a pistol-length gas system — adding velocity and improved supersonic performance over the 7.5-inch variant while keeping the build compact enough for SBR and pistol configurations.

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 10.5-inch heavy 4150 CMV parkerized barrel on a pistol-length gas system with a 1:8 twist and M-LOK handguard.

Four specs define this upper's place in the .300 BLK lineup. The 10.5-inch heavy barrel profile adds thermal mass over a standard-contour barrel, dissipating heat more effectively during sustained fire and maintaining point-of-impact consistency as the barrel warms — a meaningful advantage for .300 BLK platforms where follow-up shots on game or suppressed training sessions generate extended firing strings. Pistol-length gas system provides the correct dwell time for reliable cycling at 10.5 inches in .300 BLK, where the cartridge's gas curve differs from 5.56 and demands a gas system tuned to the chambering. A 1:8 twist rate stabilizes the full spectrum of .300 BLK projectile weights across supersonic and subsonic loads, making the upper versatile without requiring separate barrels for different use cases. The M-LOK handguard provides direct accessory attachment for lights, lasers, and grips without rail-section adapters on a platform where muzzle weight from a suppressor already adds front-end mass.

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

4150 Chrome Moly Vanadium barrel, heavy profile, 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 10.5 inches with a heavier barrel profile for sustained fire and suppressor-host use.

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