The CMMG ZEROED Banshee Mk4 SBR .300 BLK Armor Black is a short-barreled rifle that ships with a standard-length ZEROED 30 suppressor tucked beneath its oversized M-LOK handguard (brand part no. 30AE11-AB). CMMG builds it around a 6.5-inch 4140CM nitrided barrel with a 1:7 twist, a direct impingement system and an adjustable .750-inch gas block for tuning between supersonic and subsonic loads. A B5 Systems Bravo stock rides on a FASTBACK six-position receiver extension, and the ZEROED controls include an ambidextrous charging handle, a single-stage drop-in trigger, a 60/90 ambi safety and a ZEROED pistol grip. Three silicone SD-style handguard covers come in the box to keep your hands off a hot rail. It is a complete .300 BLK package for hunting, home defense or range work.

Key Specifications

• Chambering is .300 BLK, a cartridge that runs both supersonic and subsonic loads well.
• Barrel length is 6.5 inches in 4140CM with a nitride finish, short enough to keep the can under the handguard.
• Twist rate is 1:7, a rate that stabilizes heavy subsonic .30-caliber bullets.
• The muzzle device is the included ZEROED 30 suppressor on a 5/8×24 muzzle thread.
• The gas block is an adjustable .750-inch unit for tuning the gas system to suppressed fire.
• The handguard is an 11-inch M-LOK with a 1.72-inch inner diameter, sized to clear most modern suppressors.
• The stock is a B5 Systems Bravo stock on a FASTBACK six-position receiver extension.

Frequently Asked Questions

Do I need ATF approval to buy this? No. As of October 9, 2026, ATF no longer requires Form 4 approval, registration or a tax stamp for short-barreled rifles. It transfers on a Form 4473 with a background check through a Class 3 (SOT) dealer. State and local laws still apply. Taking an SBR across state lines still requires an approved ATF Form 5320.20.

Will M-LOK accessories fit around the suppressor? CMMG says the 1.72-inch inner diameter clears most modern suppressors, but accessories mounted in the slots directly around a tucked suppressor significantly reduce clearance. Always verify clearance before use.

What controls does it use? All ZEROED Banshees get CMMG’s ZEROED ambidextrous charging handle, single-stage drop-in trigger, 60/90 ambidextrous safety selector and pistol grip.

Buy the CMMG ZEROED Banshee Mk4 SBR .300 BLK with ZEROED 30 Suppressor, Armor Black

Buying the rifle and the can as one matched package means the barrel, gas block and handguard were sized for each other from the start. As of October 9, 2026, this short-barreled rifle transfers on a Form 4473 with a background check at your Class 3 (SOT) dealer, with no Form 4 or tax stamp; state and local laws still apply. Order through CMMG‘s short-barreled rifles lineup and our Lubbock, Texas team will handle the transfer, and it ships fast to your Class 3 dealer.