CMMG Banshee Mk57 SBR 5.7x28mm
Model: 57A550F
CMMG Banshee Mk57 SBR 5.7x28mm
Model: 57A550F
Full Specifications
Threaded 1/2x28 barrel: compare pistol suppressor prices.
About This Firearm
The CMMG Banshee Mk57 SBR is a radial delayed blowback 5.7x28mm built for truck or pack carry and training. It has an MSRP of $1,749.95. It feeds FN Five-seveN pattern magazines, which puts pistol magazines in a shouldered rifle of 21.3 inches and 4.9 lbs.
The EML4 handguard carries a full-length Picatinny top rail and an integrated handstop, so an optic and a hand stop are already there, with M-LOK slots at 3, 6 and 9 o'clock for a light. The safety selector runs a 60 or a 90 degree throw. A 20 round Promag comes with it, so spares are a purchase. The ZEROED Linear Compensator pushes blast forward and unscrews from 1/2x28 threads for a can.
If you're cross-shopping, the Diamondback DBX is the pistol take on the same idea, with an MSRP of $1,216, an 8 inch barrel and 3.6 lbs, running a dual gas piston action instead of blowback. The CMMG Suppressed ZEROED Banshee Mk4 SBR has an MSRP of $2,224.95 in 9mm and includes a working suppressor, where the Mk57's compensator redirects blast without quieting it.
Best For
Strengths & Limitations
- The barrel is 4140 chrome moly with an SBN finish and a 1:9 twist.
- The ZEROED trigger is a self-contained drop-in unit, so changing it does not mean fitting loose parts into the lower.
- It shares CMMG's radial delayed blowback operating system with the 9mm Banshee Mk4 guns, so the manual of arms is the same across the line.
- Armor Black is the one Cerakote color CMMG offers on this build, so another finish means paying for a refinish.
- CMMG quotes a 15 to 30 business day lead time on this build.
Ballistics Calculator
Calculate trajectory, drop, and energy for 5.7x28mm ammunition.
5.7x28mm Ballistics →Where to Buy
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Frequently Asked Questions
Does it use AR-15 parts?
The drop-in trigger and the pistol grip are AR-pattern. The lower is CMMG's own Mk57 forging, cut for Five-seveN pattern magazines, so magazine and magwell parts are specific to this platform.
How does it differ from the 9mm Banshee guns?
Caliber and magazines, mainly. The CMMG Suppressed ZEROED Banshee Mk4 SBR is the 9mm build on Glock-style capacity and comes with a suppressor; the Mk57 is the 5.7x28mm chambering with its own lower and a 1:9 barrel.
Is there a pistol version?
CMMG sells Mk57 Banshee pistols as well, and the names run close together. This one is the SBR, the build that comes with the B5 Systems Bravo shoulder stock.