CMMG MK4 Banshee 100 300 Blackout 8" Barrel 30-Round Semi-Automatic Rifle

The CMMG MK4 Banshee 100 in 300 Blackout with an 8-inch barrel is a lightweight, compact semi-automatic rifle built for shooters who prioritize portability without sacrificing capability. At just 4 lbs 11 oz unloaded and measuring 23.9 inches overall, this is the kind of firearm that makes sense for home defense, truck storage, or range sessions where maneuverability matters. The 300 Blackout cartridge pairs naturally with the short barrel—it was designed for exactly this role—and the Banshee platform delivers the accuracy and reliability you expect from CMMG.

Build quality here is straightforward and proven: forged 7075-T6 aluminum upper and AR15-pattern lower receiver with hard coat anodized finish, a CMMG RML7 M-Lok hand guard for mounting lights or other accessories, and pistol-length gas system tuning for the compact configuration. The 1:7 twist, medium-taper 4140CM barrel handles 300 Blackout rounds reliably, and the A2 muzzle device is threaded 5/8-24 for suppressor compatibility if that's in your plans. You're getting a Mil-Spec trigger, charging handle, safety, and trigger guard—nothing fancy, nothing that needs to be, just functional controls that work.

This ships with a 30-round Magpul PMAG and a CMMG pistol receiver extension with ambidextrous sling plate, so you have the magazine capacity and carrying options sorted from day one. If you're looking for a 300 Blackout platform that doesn't eat up your kit bag or your shooting shoulder, the Banshee 100 is worth a hard look.

Key Features

• 8-inch 300 Blackout barrel with 1:7 twist for reliable subsonic and supersonic ammunition
• Lightweight at 4 lbs 11 oz unloaded; compact 23.9-inch overall length
• Forged 7075-T6 aluminum receivers with hard coat anodized finish
• CMMG RML7 M-Lok hand guard for accessory mounting
• Threaded 5/8-24 A2 muzzle device for suppressor compatibility
• Pistol-length gas system optimized for short-barrel performance
• Ambidextrous sling plate on receiver extension
• Includes 30-round Magpul PMAG

Specifications

Frequently Asked Questions

Is this 300 Blackout AR pistol suppressor-ready?

Yes. The Banshee 100 comes with a threaded 5/8-24 A2 muzzle device, which is the standard suppressor thread pitch for 300 Blackout rifles. If you run a suppressor, the 8-inch barrel with pistol-length gas system is tuned to handle both subsonic and supersonic ammunition cleanly.

What's included with this rifle, and do I need to add anything?

The Banshee 100 ships with a 30-round Magpul PMAG and a receiver extension fitted with an ambidextrous sling plate. You'll need to add your own optic or sights, and consider a light or other accessories to mount on the M-Lok hand guard if that's your preference.

How small and light is this compared to other short-barrel rifles?

At 23.9 inches overall and 4 lbs 11 oz unloaded, the Banshee 100 is purpose-built for portability and quick handling. The compact footprint and low weight make it suitable for vehicle storage, close-quarters work, or any role where you need to move fast without surrendering firepower.

Is the 300 Blackout the right choice for home defense or hunting?

300 Blackout was specifically developed for short-barrel rifles and is an excellent mid-range cartridge for both roles. With an 8-inch barrel, this platform handles the round well across the subsonic and supersonic spectrum. Ammunition choice and shot placement will always be more important than caliber, so consider your specific application and load selection carefully.