The CMMG Resolute MK4 is an assembled upper receiver for AR-15 builds, chambered in 300 Blackout with a 14.5-inch barrel topped with a pinned and welded muzzle brake. The pinned and welded brake satisfies overall length compliance requirements while managing recoil, and the mid-length gas system paired with a 1-7 twist rate delivers reliable cycling and accuracy across the caliber’s range.
The EML 15 handguard features M-LOK attachment slots positioned at 3, 6, 9, and 12 o’clock, offering modern accessory mounting capability. Whether loaded with super or subsonic 300 BLK ammunition, this upper performs effectively in extended-range applications and close-quarters scenarios alike. CMMG backs this assembled upper with a Lifetime Quality Guarantee against material and workmanship defects.
