CMMG Banshee

CMMG Inc. · Carbine · In Production · 2017

Also known as: CMMG Mk9, CMMG MkGs Banshee

Overview

The CMMG Banshee is a compact AR-15 pattern pistol-caliber carbine featuring CMMG's innovative Radial Delayed Blowback (RDB) operating system. Introduced in 2017, the Banshee is available in multiple calibers including 9mm, .45 ACP, 10mm, 5.7x28mm, and .300 Blackout, with barrel lengths ranging from 5 to 8 inches depending on variant. The RDB system uses a radial cam system to delay bolt unlocking, allowing lighter bolt weights and reduced recoil compared to traditional straight blowback PCCs while maintaining reliability. The 9mm variant weighs just 4.8 pounds and features a 5-inch medium-taper threaded barrel machined from 4140 chrome-moly steel. The Banshee includes CMMG's ZEROED line of enhanced components including an ambidextrous charging handle, ambidextrous safety selector, single-stage trigger, and oversized bolt catch. The free-floating M-LOK handguard provides mounting options for accessories while the aircraft-grade aluminum receivers ensure durability. The compact design makes the Banshee ideal for personal defense, vehicle operations, and close-quarters applications.

Specifications

Weight (empty)	2177 g (76.8 oz)
Weight (loaded)	2500 g (88.2 oz)
Overall Length	533 mm (20.98")
Barrel Length	127 mm (5.00")
Height	133 mm (5.24")
Width	32 mm (1.26")
Action Type	Delayed Blowback
Firing Mechanism	Hammer Fired
Trigger Type	Single Stage
Trigger Pull	22 N (4.9 lbf)
Magazine Capacity	30 rounds
Magazine Type	Detachable Box
Muzzle Velocity	380 m/s (1247 fps)
Muzzle Energy	537 J (396 ft·lbf)
Effective Range	100 m (109 yd)
Maximum Range	1800 m (1968 yd)
Barrel Rifling	Right Hand
Rifling Twist	254 mm (10.00")
Number of Grooves	6
Frame Material	Aluminum Alloy
Barrel Material	Steel
Stock Material	Polymer
Finish	Cerakote

Calibers

9x19mm Parabellum · primary · 9mm NATO — also known as 9mm Luger, 9mm NATO, 9x19mm

Features

Firing modes: Semi Automatic
Feed systems: Detachable Box Magazine
Safety mechanisms: Manual Safety Selector, Firing Pin Safety
Features: Radial Delayed Blowback, Ar15 Pattern, Last Round Bolt Hold Open, Ambidextrous Controls, M Lok Handguard, Threaded Barrel, Picatinny Rail, Compact Design, Free Floating Handguard

Variants

Banshee 300 BLK — Rifle Caliber
Banshee 45 ACP — Pistol Caliber
Banshee 10mm — Pistol Caliber
Banshee 5.7x28mm — Pistol Caliber

Production

Production years: 2017-present

Continuous production across multiple caliber variants

Origin

Country of origin: United States

Notes

CMMG's Radial Delayed Blowback system represents a significant innovation in pistol-caliber carbine design. Traditional blowback PCCs require heavy bolts to delay opening long enough for pressure to drop safely, resulting in harsh recoil and limited cyclic rates. The RDB system uses angled lugs on the bolt that engage corresponding cuts in the barrel extension, forcing the bolt to rotate during rearward travel. This rotation delays unlocking just long enough for safe pressure reduction while allowing a much lighter bolt - the RDB bolt weighs significantly less than comparable straight blowback designs. The result is softer recoil, faster cycling, and improved reliability. The Banshee platform is available as both pistols (with arm braces) and SBRs (with stocks). CMMG manufactures the Banshee in Boonville, Missouri, and the platform has gained popularity in competitive shooting disciplines like PCC division.

Background

CMMG developed the Radial Delayed Blowback system to address the shortcomings of direct blowback pistol-caliber carbines. The company's founders, Jeff Overstreet, John, Gretchen, and Stephanie Crabtree, wanted to create a PCC that offered AR-15 ergonomics with pistol-caliber ammunition efficiency. The Banshee name reflects the weapon's compact, aggressive profile. The platform has become popular in competitive shooting, particularly 3-Gun and PCC divisions, where its light weight and soft recoil provide competitive advantages.