The CMMG Endeavor MK4 is an AR-15 pattern semi-automatic rifle chambered in .22 ARC with a 20-inch threaded barrel. Titles list a Sniper Gray Cerakote finish, a Magpul stock, and a 30-round capacity. The model number is 28A7F0CSG. 
 

Key Specifications 

• Brand: CMMG 
• Model: Endeavor MK4 
• Caliber: .22 ARC 
• Action: Semi Auto 
• Capacity: 30 rounds 
• Barrel Length: 20 in 
• Color/Finish: Sniper Gray 
   

Detailed Features 

• AR-15 platform with 20-inch threaded barrel 
• Sniper Gray Cerakote finish 
• Magpul stock 
• 30-round magazine 
• .22 ARC chambering in the MK4 configuration

Owners of the CMMG Endeavor MK4 in .22 ARC appreciate the longer 20-inch barrel paired with the cartridge, noting it extracts more velocity than shorter configurations and makes the rifle well suited for longer-range work. The Sniper Gray Cerakote finish gets consistent praise for durability and a low-profile appearance that avoids the tactical-black look.

The Magpul stock is a practical inclusion that most owners find comfortable, though some swap it out for personal preference. The threaded barrel is a feature that draws buyers who want suppressor-ready capability, and CMMG threading dimensions are described as consistent and well-cut. A few owners note that .22 ARC ammunition availability is still developing compared to more established calibers.

Build quality on the Endeavor MK4 line is generally well regarded, with tight tolerances and clean internals. The trigger divides opinion: adequate out of the box, but a common upgrade path for owners who shoot it often. CMMG support has a good reputation, which factors into buyer confidence for a rifle in a relatively new chambering.