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CMMG Mk4 .300BLK 12.5in Banshee Upper Group Receiver Up to 14% Off w/ Free Shipping — 5 models

CMMG Mk4 .300BLK Banshee Upper Group Receiver, 12.5in, Sniper Grey, 30B8A6F-SG
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 12.5in, Coyote Tan, 30B8A6F-CT
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 12.5in, Tungsten, 30B8A6F-TNG
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 12.5in, Titanium, 30B8A6F-TI
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 12.5in, Midnight Bronze, 30B8A6F-MB
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 12.5in, Sniper Grey, 30B8A6F-SG
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 12.5in, Coyote Tan, 30B8A6F-CT
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 12.5in, Titanium, 30B8A6F-TI
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 12.5in, Tungsten, 30B8A6F-TNG
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 12.5in, Midnight Bronze, 30B8A6F-MB
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 12.5in, Sniper Grey, 30B8A6F-SG
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CMMG Mk4 .300BLK Banshee Upper Group Receiver, 12.5in, Sniper Grey, 30B8A6F-SG
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 12.5in, Coyote Tan, 30B8A6F-CT
2 of 10 images
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 12.5in, Coyote Tan, 30B8A6F-CT
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 12.5in, Tungsten, 30B8A6F-TNG
3 of 10 images
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 12.5in, Tungsten, 30B8A6F-TNG
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 12.5in, Titanium, 30B8A6F-TI
4 of 10 images
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 12.5in, Titanium, 30B8A6F-TI
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 12.5in, Midnight Bronze, 30B8A6F-MB
5 of 10 images
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 12.5in, Midnight Bronze, 30B8A6F-MB
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 12.5in, Sniper Grey, 30B8A6F-SG
6 of 10 images
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 12.5in, Sniper Grey, 30B8A6F-SG
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 12.5in, Coyote Tan, 30B8A6F-CT
7 of 10 images
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 12.5in, Coyote Tan, 30B8A6F-CT
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 12.5in, Titanium, 30B8A6F-TI
8 of 10 images
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 12.5in, Titanium, 30B8A6F-TI
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 12.5in, Tungsten, 30B8A6F-TNG
9 of 10 images
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 12.5in, Tungsten, 30B8A6F-TNG
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 12.5in, Midnight Bronze, 30B8A6F-MB
10 of 10 images
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 12.5in, Midnight Bronze, 30B8A6F-MB

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Questions & Answers
Do uppers have to be delivered to a FFL?

Nope! It’s just lower receivers that have to be sent to FFLs

by Westin Linville, Verified Owner, April 11, 2025
Will this work with a Standard AR15 lower? Expert Answer

Yes, the CMMG Mk4 .300BLK 12.5in Banshee Upper Group Receiver will fit and function on Milspec AR15 lower receivers.

by Ethan, Gear Expert, January 17, 2023
View All Q&A You Have a Question? Ask!
5 Models Available
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ATTENTION! We currently do not ship this product to P.O. Boxes, AK, CA, CT, DE, HI, MA, NJ, NY, U.S. Territories, or select Colorado locations. Please see our policies for more information or a detailed list of locations.

Product Info for CMMG Mk4 .300BLK 12.5in Banshee Upper Group Receiver

Designed from day one for the AR15 platform, 300BLK was made to utilize many of the most common AR components in existence. With the 12.5 BANSHEE upper group you can build your next 300BLK AR with character like no other.image

WARNING: California`s Proposition 65

Specifications for CMMG Mk4 .300BLK 12.5in Banshee Upper Group Receiver:

Manufacturer: CMMG
Caliber: .300 AAC Blackout
Overall Length: 20.8 in
Barrel Length: 12.5 in
Barrel Profile: Medium
Gas System Length: Pistol Length
Barrel Twist Rate: 1-7
Muzzle Device: CMMG Zeroed Linear Compensator
Fabric/Material: 6061-T6 Aluminum
Gas Block Journal Size-Diameter: .750 in
Gun Rail: M-LOK
Gun Type: Rifle
Gun Make: CMMG
Gun Model: CMMG Mk4
Weight: 3.7 lb
Magazine Included: No
Mount Type: M-LOK

Package Contents:

  • CMMG Mk4 .300BLK 12.5in Banshee Upper Group Receiver

What firearm models does the manufacturer say CMMG Mk4 .300BLK 12.5in Banshee Upper Group Receiver is compatible with?

The manufacturer suggests that CMMG Mk4 .300BLK 12.5in Banshee Upper Group Receiver is compatible with CMMG Mk4

CMMG Mk4 .300BLK 12.5in Banshee Upper Group Receiver Orderable Models

List of Orderable Models

  • CMMG Mk4 .300BLK Banshee Upper Group Receiver, 12.5in, Sniper Grey, 30B8A6F-SG , MPN: 30B8A6F-SG , UPC: 810097502536 , Code: 2CM-URC-CP43-30B8A6F-SG
  • CMMG Mk4 .300BLK Banshee Upper Group Receiver, 12.5in, Coyote Tan, 30B8A6F-CT , MPN: 30B8A6F-CT , UPC: 810097502512 , Code: 2CM-URC-CP43-30B8A6F-CT
  • CMMG Mk4 .300BLK Banshee Upper Group Receiver, 12.5in, Titanium, 30B8A6F-TI , MPN: 30B8A6F-TI , UPC: 810097502543 , Code: 2CM-URC-CP43-30B8A6F-TI
  • CMMG Mk4 .300BLK Banshee Upper Group Receiver, 12.5in, Tungsten, 30B8A6F-TNG , MPN: 30B8A6F-TNG , UPC: 810097502550 , Code: 2CM-URC-CP43-30B8A6F-TNG
  • CMMG Mk4 .300BLK Banshee Upper Group Receiver, 12.5in, Midnight Bronze, 30B8A6F-MB , MPN: 30B8A6F-MB , UPC: 810097502529 , Code: 2CM-URC-CP43-30B8A6F-MB

CMMG Mk4 .300BLK 12.5in Banshee Upper Group Receiver Unavailable & Discontinued Models

List of Unorderable Models

  • CMMG Mk4 .300BLK Banshee Upper Group Receiver, 12.5in, Charcoal Green, 30B8A6F-CG , MPN: 30B8A6F-CG , UPC: 810097502505 , Code: 2CM-URC-CP43-30B8A6F-CG
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Last updated 2026-09-24 UTC.