The CMMG Endeavor Mk4 is a semi-automatic rifle chambered in .22 ARC (223 Rem), built on a forged 7075 T-6 aluminum frame and receiver with a 20-inch stainless steel barrel finished in black nitride. The Midnight Bronze Armor Cerakote finish is distinctive without being garish. At 6.8 lbs (7 lbs with stock), it stays manageable for extended range sessions. 
 

Key Specifications 

• Model: Endeavor Mk4 
• Caliber: .22 ARC - 223 Rem 
• Action: Direct Impingement 
• Barrel Length: 20 inches 
• Capacity: 10 Rounds (Max capacity of 30 rounds) 
• Finish: Midnight Bronze Armor Cerakote 
• Frame Material: Forged 7075 T-6 Aluminum 
• Receiver Material: Forged 7075 T-6 Aluminum 
• Weight: 6.8 lbs (7 lbs with stock) 
   

Detailed Features 

The direct impingement system uses gas from fired cartridges to cycle the action. The barrel is threaded and accepts standard muzzle devices; CMMG includes their Zeroed Muzzle Brake, which cuts felt recoil enough to matter for follow-up shots. The EML M-Lok handguard gives mounting space for optics and accessories without adding meaningful weight. Magpul components cover the grip and adjustable stock, both made from synthetic materials. 
 

Target Audience 

This rifle works for shooters who want a .22 ARC platform with quality components out of the box. The Magpul adjustable stock accommodates different body types and shooting positions, so it fits a range of users without modification. 
 

Usage Scenarios 

The 20-inch barrel and .22 ARC caliber are well matched for target shooting at range. The muzzle brake and direct impingement action keep the platform flat during rapid fire, which helps in competitive shooting. For casual range use or training, the reduced recoil and adjustable ergonomics make it straightforward to shoot for extended periods.

Owners of the CMMG Endeavor Mk4 in .22 ARC with Midnight Bronze finish talk about it mostly in positive terms, with a few consistent caveats.

The Midnight Bronze Cerakote finish gets mentioned frequently. It has a look that distinguishes it from standard black rifles without crossing into garish territory. Build quality earns consistent praise; the forged 7075 T-6 aluminum frame and quality component selection give the rifle a solid feel that owners notice and reference when comparing it to other ARs in the price range.

Accuracy is the other major talking point. Shooters report good results at various distances, and the .22 ARC caliber performs well for the applications most owners describe, target practice and small game hunting. The manageable recoil and Zeroed Muzzle Brake make it comfortable for extended range sessions.

The criticisms tend to cluster around price and accessories. Some shooters feel the cost is high relative to comparable rifles from other manufacturers, and that conversation comes up often in forum discussions. The .22 ARC platform also has a growing but still limited aftermarket compared to more established calibers, though the M-Lok handguard and Magpul components mean standard accessories fit without issue. CMMG has a reasonably active user community, and owners share upgrade paths and configurations freely.