Platform | Mk4 |
Caliber | 5.56x45mm |
Operating System | Direct Impingement |
Barrel Length | 12.5 |
Barrel Twist | 1:7 |
Barrel Contour | MR |
Barrel Material | 4140CM, SBN |
Barrel Twist | 1:7 |
Muzzle Device | CMMG ZEROED Linear Compensator |
Muzzle Thread | 1/2 x 28 |
Gas Port Location | Carbine |
Gas Block | 0.750 Non-Adjustable |
Upper Receiver | Billet 6061 T6 Aluminum |
Hand Guard | CMMG EML11 M-LOK |
Finish | Cerakote Standard |
Charging Handle | CMMG ZEROED Ambi |
Weight | 3.8 lbs |
Length | 20.8" |







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Expected to ship within 15-30 business days. Build to Order products are items that are not built but all components are in stock and ready for assembly.
THIS PRODUCT IS BACKED BY THE CMMG LIFETIME QUALITY GUARANTEE.
UPPER GROUP, BANSHEE, Mk4, 5.56X45MM NATO, 12.5"
Pair this 12.5” 5.56mm BANSHEE™ upper group with the Mk4/standard AR15 lower group of your choice to create a compact AR pistol or SBR that blends maneuverability with carbine like ballistic performance. Available in different Cerakote finishes, all CMMG® Upper Groups come complete with bolt carrier group and ZEROED™ accessories including:
ZEROED AR15 Polymer Dust Cover
ZEROED AR15 Ambi Charging Handle
ZEROED Linear Compensator 5.56mm
We aim to please, that’s why every CMMG product is backed by our Lifetime Quality Guarantee against material and workmanship defects. Learn More.