Brigade Bm-300 300Blk 7.5 Mb Sba3 Mlok A2

The Brigade BM-300 is a .300 Blackout AR-15 pistol built for serious short-range work—suppressed shooting, close-quarters drills, or a compact truck gun. With a 7.5-inch barrel and SBA3 brace, it's maneuverable without sacrificing the ballistic performance of .300 Blackout. The receiver is forged 7075-T6 aluminum, CNC-machined for precision fit, while the barrel is 4150 chrome-moly with a nitride finish and 1:7 twist optimized for heavier subsonic and supersonic loads. This is a genuine AR platform pistol, not a short-barreled rifle, so it works as-is in most states—but always verify your local laws.

The BM-300 runs a direct impingement gas system with a mil-spec trigger, 5.56 bolt carrier group, and ambi charging handle for left- or right-handed operation. The 7-inch M-Lok rail gives you real estate for optics, lights, and pressure switches. A2 flash hider threads 5/8x32 for easy suppressor swap-out, and the 3-ounce buffer keeps things running smooth. You get a 30-round magazine in the box and the SBA3 brace—a comfortable, adjustable stabilizing brace that lets you fire from the wrist.

This is the gun for hunters who want subsonic punch in tight spaces, shooters running drills on a budget, or anyone building a truck-gun battery. Brigade Arms keeps the engineering straightforward: solid forgings, mil-spec parts, good triggers. No gimmicks—just a proven platform in an underrated caliber.

Key Features

• 7.5-inch 4150 chrome-moly barrel with nitride finish and 1:7 twist for .300 Blackout performance
• 7075-T6 forged aluminum upper and lower receivers, CNC-machined for tight tolerances
• Direct impingement gas system with mil-spec trigger and ambi charging handle
• 7-inch M-Lok rail for optics, lights, and accessories
• A2 flash hider with 5/8x32 threading for suppressor compatibility
• SBA3 tactical brace for stability and control
• Includes 30-round magazine and 3-ounce buffer
• AR-15 platform with 5.56 bolt carrier group—uses standard AR parts and ammunition handling

Specifications

Frequently Asked Questions

Is the Brigade BM-300 a pistol or a short-barreled rifle?

This is an AR-15 pistol, meaning it ships with the SBA3 stabilizing brace and no stock. It meets federal pistol definitions, but always verify your state and local laws before purchase—some jurisdictions have restrictions on pistol braces or short-barreled configurations.

Can I use .300 Blackout ammunition in this gun?

Yes. The BM-300 is chambered in .300 Blackout and will handle both supersonic and subsonic loads. The 1:7 barrel twist is optimized for the full range of .300 Blackout offerings.

Will a suppressor fit on this barrel?

The barrel is threaded 5/8x32, which is the standard .300 Blackout suppressor thread pitch. Any 5/8x32-threaded suppressor will mount directly once you unscrew the A2 flash hider.

What comes in the box?

The Brigade BM-300 includes the complete assembled upper and lower, SBA3 brace, one 30-round magazine, and the A2 flash hider already installed on the barrel.