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CMMG
Overview
The CMMG Resolute Mk4 338 ARC 16.1 Barrel Upper Receiver Group is a complete assembly designed for builders looking to enhance their AR-15 platform with a 300 Blackout caliber option. With a barrel length of 16.1 inches, this upper receiver group offers a balance of maneuverability and accuracy, making it suitable for both close-quarters engagements and moderate-range shooting. This product is often found in versatile builds where adaptability and performance in various shooting scenarios are prioritized.
Specifications
CMMG Resolute MK4 338 ARC 16.1 Barrel Upper Receiver Group
Build history on GunPartPicker
Builders have been adding the CMMG Resolute MK4 338 ARC 16.1 Barrel Upper Receiver Group to their builds on GunPartPicker since April 2026. All time, it ranks #489 of the 1,711 upper receivers builders have added.
It was out of stock everywhere we track for all of September 2026, and today only Optics Planet has it in stock. Buying today, the lowest price is $789.99 at Optics Planet, above September's low of $641.91, so a better deal may come back.
Updated · from real builds on GunPartPicker · Prices checked · refreshed daily across 37 retailers
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Frequently Built With
The part most often added in each category by the builds that include this one
PSA AR-15 Complete Lower Magpul MOE EPT Edition - Flat Dark Earth, No Magazine
FAXON Firearms 5.56 M16 Bolt Carrier Group Nitride TIN PVD
Geissele Automatics AR-15 SSA X Lightning Bow Trigger
Magpul AFG Angled Fore Grip - Black
MAGPUL UBR GEN 2 STOCK
Radian Raptor Slim Line Ambidextrous AR-15 Charging Handle - Black
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