| Platform | Mk57 |
| Caliber | 5.7x28mm |
| Operating System | Radial Delayed Blowback |
| Barrel Length | 5 |
| Barrel Twist | 1:9 |
| Barrel Contour | MT |
| Barrel Material | 4140CM, SBN |
| Barrel Twist | 1:9 |
| Muzzle Device | CMMG ZEROED Linear Compensator |
| Muzzle Thread | 1/2 x 28 |
| Gas Port Location | N/A |
| Gas Block | N/A |
| Upper Receiver | Billet 6061 T6 Aluminum |
| Lower Receiver | Mk57 Forged 7075 T6 Aluminum |
| Hand Guard | CMMG EML4 M-LOK |
| Finish | Cerakote |
| Charging Handle | CMMG ZEROED Ambi |
| Pistol Grip | CMMG ZEROED Pistol Grip |
| Buffer Type | Carbine |
| Receiver Extension | CMMG 6 Position Fastback w/Ambi Sling Plate |
| Stock / Brace | CMMG RipStock |
| Trigger Type | ZEROED Drop-In |
| Trigger Guard | Integrated |
| Safety Selector | CMMG ZEROED 60/90 Degree |
| Magazine | 20rd Promag |
| Weight | 4.9 lbs |
| Length | 21.3" |
Please Allow 15-30 Days To Process Your Order.
State/local restrictions may apply in CA, CO, CT, DE, DC, HI, IL, MD, MA, MI, NJ, NY, or WA. Customers must review our Firearms Shipping Policy prior to ordering.
Firearms with attached pistol brace. Please confirm your FFL is accepting transfers for pistol brace equipped firearms prior to ordering.
SBR, BANSHEE, Mk57, 5.7x28mm, 5"
Interchangeability matters, that’s why the Mk57™ is not only chambered in the same caliber, 5.7x28mm, as other popular PDWs and pistols, but the BANSHEE™ Mk57 SBR uses FN®* Five-seveN®* pattern magazines. Not only do shooters get more ways to use their mags, the Mk57 still brings the full set of AR15 features, making rifle operation second nature. With 5” barrel this is the smallest Mk57 SBR CMMG® has to offer.
Available in a range of cerakote finishes, the BANSHEE series represents the most innovative AR pistols and SBRs available today. From the quick deploying RIPSTOCK®, to the stylized receivers and EML™ handguards, every BANSHEE is tailor-made to be the personal defense weapon you can always depend on. New EML4 handguards feature M-LOK® slots at 3, 6, & 9 o’clock positions and a full length picatinny top rail for accessories as well as an integrated handstop.
Radial Delayed Blowback™ Operating System
Originally developed for the .45 ACP MkG platform, CMMG has adapted our Radial Delayed Blowback system across our pistol caliber lineup to create pistols and rifles with a softer recoil impulse and reduced bolt weight compared to traditional straight blowback systems. Check out our CMMG Resources article & video to learn more about what sets Radial Delayed Blowback apart.
**All NFA rules apply** All BANSHEE NFA SBRs (short barrel rifles) require additional ATF paperwork & processing time. See linked CMMG Resource article for more information.
Mk57 ZEROED parts and accessories – Quality comes standard
The AR platform is well known for its capability for customization but picking the right parts doesn’t have to be a nightmare of homework. Everything from the RIPSTOCK to the full kit of ZEROED parts and accessories are made here in the USA with quality and attention to detail that is second to none and each BANSHEE comes equipped with a slew of ZEROED parts standard, including:
ZEROED AR15 Ambi Charging Handle
ZEROED AR15 Polymer Dust Cover
ZEROED Linear Compensator 45ACP
Lifetime Quality Guarantee
We aim to please, that’s why every CMMG product is backed by our Lifetime Quality Guarantee against material and workmanship defects. Learn More.
~Firearms shipping to states with magazine capacity restrictions will only ship with 10rd magazines in place of standard capacity magazines. CMMG does not address any other state compliancy requirements for further restricted states.
