The CMMG Resolute MK4 Upper Group (brand part number 35B5FBCAB) is chambered in .350 Legend, a straight-walled cartridge introduced in 2019 that gives deer hunters in states with caliber restrictions a round delivering solid power on target with noticeably less recoil than options like .30-30 Winchester or .243 Winchester. Built by CMMG with a 16.1-inch barrel, this Direct Impingement upper is designed to work with any standard AR15 lower group and ships complete with a bolt carrier group and CMMG’s ZEROED accessories, including a polymer dust cover, an ambidextrous charging handle, and a 9mm-pattern muzzle brake, all finished in Cerakote.

Key Specifications

• Chambered in .350 Legend on the Mk4 platform.
• Barrel length is 16.1 inches.
• Operating system is direct impingement.
• Twist rate is 1:16, matched to .350 Legend bullet weights.
• Barrel material is 4140 chromoly steel with a salt bath nitride finish.
• Muzzle device is a CMMG ZEROED muzzle brake, threaded 1/2×28.
• Gas system is carbine-length with a 0.750-inch non-adjustable gas block.
• Upper receiver is billet 6061-T6 aluminum with an EML15 M-LOK handguard.
• Includes a CMMG ZEROED ambidextrous charging handle and bolt carrier group.
• Weighs approximately 4.0 pounds with a 25-inch overall length.

Frequently Asked Questions

Why choose .350 Legend for hunting? It is a straight-walled cartridge that meets many state hunting requirements while offering less recoil than comparable straight-walled options.

Does this upper include a bolt carrier group? Yes, all CMMG Upper Groups ship complete with a bolt carrier group and CMMG’s ZEROED accessories.

Buy the CMMG Resolute MK4 .350 Legend Upper Group

Build a low-recoil, straight-walled hunting AR for caliber-restricted states. Order this AR-15 upper from our Lubbock, Texas gun shop for fast, insured shipping to your door.