The CMMG Endeavor Mk4 in .22 ARC (MPN 28A7F0C-AB) delivers .22-250-class performance out of the lighter-weight AR-15 Mk4 platform, chambered for the Advanced Rifle Cartridge and fitted with a 20-inch barrel. CMMG builds the barrel from 4140 chrome-moly with a nitride finish and a 1:7-inch twist, running a billet 6061-T6 aluminum upper over a forged 7075-T6 Mk4 lower with an adjustable 0.750 gas block. The rifle carries the CMMG ZEROED muzzle brake, ambidextrous charging handle, pistol grip, single-stage drop-in trigger, and 60/90-degree safety selector, finished in Cerakote over a Magpul MOE rifle stock. Among AR-platform rifles in the AR rifles category, the Endeavor Mk4 favors marksmen who want .22-250-class reach in a lightweight AR platform.

Key Specifications

• Chambered in .22 ARC (Advanced Rifle Cartridge) with a 1:7-inch rate of twist.
• Features a 20-inch nitride-finished 4140 chrome-moly barrel.
• Runs an adjustable 0.750 gas block.
• Upper receiver is billet 6061-T6 aluminum; lower is forged 7075-T6.
• Includes the CMMG ZEROED muzzle brake, threaded 1/2×28.
• The trigger is a CMMG ZEROED single-stage drop-in design.
• The charging handle and pistol grip are CMMG ZEROED components.
• The safety selector is a CMMG ZEROED 60/90-degree design.
• Fitted with a Magpul MOE rifle stock.
• Feeds from a 10-round CMMG magazine, weighing approximately 6.8 pounds.

Frequently Asked Questions

What is .22 ARC? A cartridge built to deliver .22-250-class velocity and reach from a standard AR-15-length platform.

What trigger does this rifle use? The CMMG ZEROED single-stage drop-in trigger.

Is the gas block adjustable? Yes, an adjustable 0.750 gas block.

Buy the CMMG Endeavor Mk4 .22 ARC

.22-250-class reach in a lightweight AR platform is exactly what the Endeavor Mk4 delivers. Order it from our Lubbock, Texas gun shop for fast, insured shipping to your FFL.