CMMG BANSHEE Mk4 9mm NFA SBR, 8.5 in Threaded Barrel, Radial Delayed Blowback, Matte Gray
This CMMG BANSHEE Mk4 is a factory 9mm NFA SBR built on the AR-15 platform with CMMG's radial delayed blowback system and an 8.5 inch threaded barrel. It features a slick-side upper, Radian Raptor ambidextrous charging handle, and a B5 Systems Bravo adjustable stock. The rifle is finished in matte gray with a continuous 1913 Picatinny top rail and includes two 33-round CMMG 9mm conversion magazines.
The Mk4 configuration uses an AR-15 magwell adapted for CMMG's 9mm conversion magazines, delivering 33+1 capacity in a compact, full-size package. The free-float M-LOK aluminum handguard and aluminum receivers keep weight down while providing modern mounting options. The receiver extension is marked FASTBACK, and controls include a right-side bolt catch/release with a manual safety.
Condition
Overall Condition: Excellent condition, showing only faint signs of any prior use or handling.
Bore Condition: Excellent - Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent Rifling - Sharp lands and grooves.
Specific Condition Notes: There are only minimal handling marks visible on exterior surfaces. See the photos for close-ups.
What’s Included
- No case included
- Two 33-round CMMG 9mm AR conversion polymer magazines
This BANSHEE Mk4 is set up as a short-barreled rifle with a stock, not a brace, and is configured for 9mm Luger. The radial delayed blowback action is purpose-built for pistol calibers and pairs here with a compact 8.5 inch threaded barrel.
The upper receiver is slick-side with no forward assist and includes an ejection-port dust cover. A continuous 1913 Picatinny rail runs across the receiver and handguard. The charging handle is a Radian Raptor and ambidextrous.
The handguard is a free-float M-LOK aluminum unit, and the rifle uses a B5 Systems Bravo adjustable stock with a QD socket. The receiver extension is marked FASTBACK. Furniture includes a CMMG-branded polymer pistol grip.
The Mk4 AR-15 magwell is configured for CMMG 9mm conversion magazines and this rifle ships with two 33-round magazines, giving a 33+1 capacity. The finish is matte gray over aluminum receivers, and the rifle is made in the USA.
As an NFA SBR, this configuration offers a compact 9mm carbine solution with modern controls, a manual safety, and an 11.0 inch length of pull.