CMMG MK4 .300BLK Banshee Upper Group Receiver 8in 1-7 Twist 5/8 X 24 TPI 16.5in Tungsten
3 options
- Coyote · Tanout of stock
- Midnight · Bronzeout of stock
- Tungsten, this page
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CMMG
Overview
The CMMG Mk4 .300BLK Banshee Upper Group Receiver is a complete upper designed for the AR-15 platform, featuring an 8-inch barrel optimized for the .300 Blackout caliber. With a 1:7 twist rate, it effectively stabilizes a range of bullet weights, making it versatile for both supersonic and subsonic loads. The 5/8x24 thread pitch allows for the attachment of a variety of muzzle devices. This upper commonly appears in compact, tactical builds that prioritize maneuverability and versatility in close-quarters engagements.
Specifications
CMMG MK4 .300BLK Banshee Upper Group Receiver 8in 1-7 Twist 5/8 X 24 TPI 16.5in Tungsten
3 options
- Coyote · Tanout of stock
- Midnight · Bronzeout of stock
- Tungsten, this page
Build history on GunPartPicker
Builders on GunPartPicker first added the CMMG MK4 .300BLK Banshee Upper Group Receiver 8in 1-7 Twist 5/8 X 24 TPI 16.5in Tungsten to a build in May 2026.
Today the one retailer we track is out of stock. Listed prices start at $799.99 at Optics Planet for when it comes back.
Updated · from real builds on GunPartPicker · Prices checked · refreshed daily across 36 retailers
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