The CMMG Banshee MK4 is a semi-automatic pistol chambered in 5.7x28mm with a 40-round capacity and a lightweight aluminum frame. At 4.6 lbs it handles well enough for sport shooting or home defense without feeling cumbersome. 
 

Key Specifications 

• Model: Banshee MK4 
• Caliber: 5.7 x 28mm 
• Barrel Length: 5 inches 
• Capacity: 40 rounds 
• Weight: 4.6 lbs 
• Finish Color: Coyote Tan 
• Manufacturer: CMMG 
• Action Type: Semi-Auto 
   

Detailed Features 

The ZEROED pistol grip and trigger guard are sized for comfortable use during extended sessions. An ambidextrous 60/90-degree safety lever, extended magazine release, and ambi charging handle round out the control layout. The blowback action pairs with a linear compensator to reduce muzzle rise, and the high-strength aluminum frame keeps weight down without sacrificing durability.

Owners of the CMMG Banshee MK4 5" in 5.7x28mm tend to be genuinely enthusiastic, with a few consistent reservations.

On the positive side, the compact size gets frequent mentions. It's easy to handle at the range and practical for home defense. The lightweight build is appreciated by anyone carrying it for extended periods. The 5.7x28mm round earns praise for its low recoil and high velocity, and the platform's compatibility with aftermarket accessories lets owners configure it however they want. Build quality is generally viewed as solid, with good attention to fit and finish.

The main criticisms are predictable: the price is higher than comparable options, and 5.7x28mm ammunition can be harder to find and costs more than common calibers. A small number of experienced shooters feel the cartridge trades too much stopping power for its recoil advantage. A few users also find the controls less intuitive than what they're used to on other pistols.