+1-800-504-5897 Live Chat Help Center Check Order Status
About Us Policies Reviews How To
Free Shipping & Free Returns*

FREE SHIPPING on Over 250,000 Products

Enjoy free shipping during the holidays! Shop now and get Free Value Shipping on most orders over $49 to the contiguous 48 states, DC and to all U.S. Military APO/FPO/DPO addresses.

Enjoy Our Extended FREE RETURNS

We want to ensure that making a return is as easy as possible! With our Hassle-Free, Extended Holiday Returns, eligible orders placed from November 12, 2025 on will benefit from an extended return deadline (January 13, 2026 or 30 days after receipt of your order - whichever is later). We'll even cover the cost of return shipping. Learn more about our Return Policy.

  • Entire Store
  • ...
  • Apparel & Footwear
  • Astronomy
  • Everything Else
  • Eyewear
  • Hunting Gear
  • Lab Equipment
  • Military Gear
  • Outdoor Gear
  • Photography Equipment
  • Police, EMS & Fire
  • Shooting
  • Sport Optics
  • Sports & Hobbies
TIP
Shopping Cart

CMMG Mk4 .300BLK 8in Banshee Upper Group Receiver Up to $79.96 Off w/ Free Shipping — 11 models

CMMG Mk4 .300BLK Banshee Upper Group Receiver, 8in, Midnight Bronze, 30B81F4-MB
CMMG Mk4 Banshee Upper Receiver Group, .300 AAC Blackout, 8in, Armor Black, 30B81F4-AB
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 8in, Charcoal Green, 30B81F4-CG
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 8in, Coyote Tan, 30B81F4-CT
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 8in, Tungsten, 30B81F4-TNG
CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Midnight Bronze, 30B12BB-MB
CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Tungsten, 30B12BB-TNG
CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Sniper Grey, 30B12BB-SG
CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Coyote Tan, 30B12BB-CT
CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Titanium, 30B12BB-TI
CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Charcoal Green, 30B12BB-CG
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 8in, Midnight Bronze, 30B81F4-MB
CMMG Mk4 Banshee Upper Receiver Group, .300 AAC Blackout, 8in, Armor Black, 30B81F4-AB
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 8in, Charcoal Green, 30B81F4-CG
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 8in, Tungsten, 30B81F4-TNG
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 8in, Coyote Tan, 30B81F4-CT
CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Tungsten, 30B12BB-TNG
CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Midnight Bronze, 30B12BB-MB
CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Coyote Tan, 30B12BB-CT
CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Sniper Grey, 30B12BB-SG
CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Titanium, 30B12BB-TI
CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Charcoal Green, 30B12BB-CG
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 8in, Midnight Bronze, 30B81F4-MB
1 of 22 images
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 8in, Midnight Bronze, 30B81F4-MB
CMMG Mk4 Banshee Upper Receiver Group, .300 AAC Blackout, 8in, Armor Black, 30B81F4-AB
2 of 22 images
CMMG Mk4 Banshee Upper Receiver Group, .300 AAC Blackout, 8in, Armor Black, 30B81F4-AB
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 8in, Charcoal Green, 30B81F4-CG
3 of 22 images
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 8in, Charcoal Green, 30B81F4-CG
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 8in, Coyote Tan, 30B81F4-CT
4 of 22 images
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 8in, Coyote Tan, 30B81F4-CT
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 8in, Tungsten, 30B81F4-TNG
5 of 22 images
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 8in, Tungsten, 30B81F4-TNG
CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Midnight Bronze, 30B12BB-MB
6 of 22 images
CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Midnight Bronze, 30B12BB-MB
CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Tungsten, 30B12BB-TNG
7 of 22 images
CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Tungsten, 30B12BB-TNG
CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Sniper Grey, 30B12BB-SG
8 of 22 images
CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Sniper Grey, 30B12BB-SG
CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Coyote Tan, 30B12BB-CT
9 of 22 images
CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Coyote Tan, 30B12BB-CT
CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Titanium, 30B12BB-TI
10 of 22 images
CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Titanium, 30B12BB-TI
CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Charcoal Green, 30B12BB-CG
11 of 22 images
CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Charcoal Green, 30B12BB-CG
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 8in, Midnight Bronze, 30B81F4-MB
12 of 22 images
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 8in, Midnight Bronze, 30B81F4-MB
CMMG Mk4 Banshee Upper Receiver Group, .300 AAC Blackout, 8in, Armor Black, 30B81F4-AB
13 of 22 images
CMMG Mk4 Banshee Upper Receiver Group, .300 AAC Blackout, 8in, Armor Black, 30B81F4-AB
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 8in, Charcoal Green, 30B81F4-CG
14 of 22 images
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 8in, Charcoal Green, 30B81F4-CG
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 8in, Tungsten, 30B81F4-TNG
15 of 22 images
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 8in, Tungsten, 30B81F4-TNG
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 8in, Coyote Tan, 30B81F4-CT
16 of 22 images
CMMG Mk4 .300BLK Banshee Upper Group Receiver, 8in, Coyote Tan, 30B81F4-CT
CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Tungsten, 30B12BB-TNG
17 of 22 images
CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Tungsten, 30B12BB-TNG
CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Midnight Bronze, 30B12BB-MB
18 of 22 images
CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Midnight Bronze, 30B12BB-MB
CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Coyote Tan, 30B12BB-CT
19 of 22 images
CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Coyote Tan, 30B12BB-CT
CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Sniper Grey, 30B12BB-SG
20 of 22 images
CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Sniper Grey, 30B12BB-SG
CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Titanium, 30B12BB-TI
21 of 22 images
CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Titanium, 30B12BB-TI
CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Charcoal Green, 30B12BB-CG
22 of 22 images
CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Charcoal Green, 30B12BB-CG

Tap Tap to Zoom

Government Export Restriction Government Export Restriction
Government Restriction Government Restriction
Questions & Answers
does this have adjustable gas block?

No, it does not have adjustable had block.

by Da, Verified Owner, March 19, 2025
Does this include a BCG? Expert Answer

Yes, the CMMG Mk4 .300BLK Banshee Upper Group Receiver will include a BCG and charging handle.

by Ethan, Gear Expert, March 15, 2024
View All Q&A You Have a Question? Ask!
11 Models Available
Overall Length
All
Barrel Length
All
Muzzle Device
All
Color
All
Search

Product Info for CMMG Mk4 .300BLK 8in Banshee Upper Group Receiver

300BLK has proven itself to be an incredibly capable round in a variety of applications, from close quarters to mid-range and ammo loadings optimized for subsonic/suppressed as well as supersonic, there is use for almost every need. Whether youre looking to swap your current AR15 upper to quickly switch to 300BLK or looking to top off a new build, this 8 BANSHEE upper group is sure to satisfy anyone looking for one of the most compact and stylish 300BLK upper groups made today.image

WARNING: California`s Proposition 65

Specifications for CMMG Mk4 .300BLK 8in Banshee Upper Group Receiver:

Manufacturer: CMMG
Caliber: .300 AAC Blackout
Barrel Profile: Medium Tapered
Barrel Twist Rate: 1-7
Threads per Inch: 5/8x24
Finish: Cerakote
Gas Block Journal Size-Diameter: .750 in
Gun Rail: M-LOK
Gun Type: Rifle
Gun Make: CMMG
Gun Model: CMMG Mk4
Magazine Included: No

Package Contents:

  • CMMG Mk4 .300BLK 8in Banshee Upper Group Receiver

What firearm models does the manufacturer say CMMG Mk4 .300BLK 8in Banshee Upper Group Receiver is compatible with?

The manufacturer suggests that CMMG Mk4 .300BLK 8in Banshee Upper Group Receiver is compatible with CMMG Mk4

CMMG Mk4 .300BLK 8in Banshee Upper Group Receiver Orderable Models

List of Orderable Models

  • CMMG Mk4 .300BLK Banshee Upper Group Receiver, 8in, 1-7 Twist, 5/8 X 24 TPI, 16.5in, Midnight Bronze, 30B81F4-MB , MPN: 30B81F4-MB , UPC: 810097502598 , Code: 2CM-URC-CP44-30B81F4-MB
  • CMMG Mk4 .300BLK Banshee Upper Group Receiver, 8in, 1-7 Twist, 5/8 X 24 TPI, 16.5in, Armor Black, 30B81F4-AB , MPN: 30B81F4-AB , UPC: 810097502567 , Code: 2CM-URC-CP44-30B81F4-AB
  • CMMG Mk4 .300BLK Banshee Upper Group Receiver, 8in, 1-7 Twist, 5/8 X 24 TPI, 16.5in, Charcoal Green, 30B81F4-CG , MPN: 30B81F4-CG , UPC: 810097502574 , Code: 2CM-URC-CP44-30B81F4-CG
  • CMMG Mk4 .300BLK Banshee Upper Group Receiver, 8in, 1-7 Twist, 5/8 X 24 TPI, 16.5in, Coyote Tan, 30B81F4-CT , MPN: 30B81F4-CT , UPC: 810097502581 , Code: 2CM-URC-CP44-30B81F4-CT
  • CMMG Mk4 .300BLK Banshee Upper Group Receiver, 8in, 1-7 Twist, 5/8 X 24 TPI, 16.5in, Tungsten, 30B81F4-TNG , MPN: 30B81F4-TNG , UPC: 810097502628 , Code: 2CM-URC-CP44-30B81F4-TNG
  • CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Sniper Grey, 30B12BB-SG , MPN: 30B12BB-SG , UPC: 810097502468 , Code: 2CM-URC-CP44-30B12BB-SG
  • CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Tungsten, 30B12BB-TNG , MPN: 30B12BB-TNG , UPC: 810097502482 , Code: 2CM-URC-CP44-30B12BB-TNG
  • CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Coyote Tan, 30B12BB-CT , MPN: 30B12BB-CT , UPC: 810097502444 , Code: 2CM-URC-CP44-30B12BB-CT
  • CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Midnight Bronze, 30B12BB-MB , MPN: 30B12BB-MB , UPC: 810097502451 , Code: 2CM-URC-CP44-30B12BB-MB
  • CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Charcoal Green, 30B12BB-CG , MPN: 30B12BB-CG , UPC: 810097502437 , Code: 2CM-URC-CP44-30B12BB-CG
  • CMMG Mk4 .300BLK Resolute Upper Group Receiver, 16.1in, Titanium, 30B12BB-TI , MPN: 30B12BB-TI , UPC: 810097502475 , Code: 2CM-URC-CP44-30B12BB-TI

CMMG Mk4 .300BLK 8in Banshee Upper Group Receiver Unavailable & Discontinued Models

List of Unorderable Models

  • CMMG Mk4 .300BLK Banshee Upper Group Receiver, 8in, 1-7 Twist, 5/8 X 24 TPI, 16.5in, Sniper Grey, 30B81F4-SG , MPN: 30B81F4-SG , UPC: 810097502604 , Code: 2CM-URC-CP44-30B81F4-SG
  • CMMG Mk4 .300BLK Banshee Upper Group Receiver, 8in, 1-7 Twist, 5/8 X 24 TPI, 16.5in, Titanium, 30B81F4-TI , MPN: 30B81F4-TI , UPC: 810097502611 , Code: 2CM-URC-CP44-30B81F4-TI
Compare (0)
1 item has been added
Add at least two items to compare