Brand: CMMG
Model: Resolute MK4
Compatibility: AR-15
Attachment Style: M-LOK
Caliber: 5.56x45mm
Operating System: Mid-Length, Direct Impingement
Barrel Length: 16.1
Barrel Twist: 1:7
Barrel Material: 4140CM, SBN
Muzzle Device: CMMG A2 Flash Hider
Muzzle Thread: 1/2 x 28
Gas Block: .750" Non-Adjustable
Upper Receiver: Billet 6061 T6 Aluminum
Hand Guard: CMMG EML15 M-LOK
Color: Midnight Bronze
Finish: Cerakote
Weight: 3.6 lbs
Length: 25"

Features

Top off your next AR build with the CMMG RESOLUTE Mk4 Upper Group, a versatile and dependable choice for shooters looking to expand their platform. Chambered in 5.56mm NATO, this upper is a solid addition to any collection—perfect for upgrading or converting your AR-15 to a reliable carbine configuration.

Compatible with any standard AR-15 lower receiver, the RESOLUTE Mk4 Upper features CMMG’s quality craftsmanship and proven design for consistent performance. Whether you’re building from scratch or swapping calibers, this upper offers an easy and effective solution.

Note: Bolt carrier group and charging handle are not included.

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Shipping Restrictions

It is the customer’s responsibility for understanding state laws regarding all purchases made. For a comprehensive list of all Shipping Restrictions, please refer to our Shipping Restrictions By State Page found Here.

All NFA Rules Apply

These items are controlled by the U.S. Government and authorized for export only to the country of ultimate destination for use by the ultimate consignee or end-user(s) herein identified. They may not be resold, transferred, or otherwise disposed of, to any other country or to any person other than the authorized ultimate consignee or end-user(s), either in their original form or after being incorporated into other items, without first obtaining approval from the U.S. government or as otherwise authorized by U.S. law and regulations.

Local Law Compliance

Certain firearm parts and accessories, including AR-style upper receivers, are subject to complex and frequently changing federal, state, and local laws and regulations. While an upper receiver may be lawfully sold and shipped as a component, the legality of possessing, assembling, configuring, or using an upper receiver in certain states (e.g., California, Washington State) and localities depends on how it is assembled, combined with other components, and ultimately used. You are solely responsible for ensuring that any assembly, configuration, possession, or use complies with all federal, state, and local laws, including any so-called “assault weapon” bans and short-barreled rifle restrictions. We do not provide legal advice and are not responsible for unlawful configurations or uses.