(5 ratings)
BCM's M4 upper receiver is forged from 7075-T6 aluminum and machined with M4 feed ramps, a 1913 flat-top rail, and a forward assist and dust cover pre-installed. The receiver is designed to tight mil-spec tolerances and ships with the T-marked rail for accessory indexing. BCM uppers are known for their consistent tight fit with BCM lowers, and they pair acceptably with most quality third-party lowers without excessive wobble. The forward assist uses BCM's proprietary ratchet teeth design that provides positive engagement. Available both as a stripped receiver and as an assembled unit with a properly staked dust cover and installed forward assist. BCM uppers are a benchmark quality reference for the mil-spec tier.
Sponsored
Right to Bear
They stand with you — no matter how tough the case
No recoupment clause means they don't come back for their money if things get complicated.
Get CoverageHave one to sell?
Current
$205.00
Lowest
$93.61
Highest
$205.00
Sign in to save a target price and receive an email when this component drops.
Sign In to Set AlertGuide
A comprehensive overview of every major component in an AR-15 build—including what's inside bolt carrier groups and parts kits—organized by assembly for new builders.
12 min read
Guide
A neutral guide to component strategies for left-handed shooters, left-eye dominant right-handed shooters, and those managing eye/hand dominance mismatches. Covers ambi uppers, charging handles, gas system tuning, and real-world tradeoffs.
6 min read