The CMMG Banshee MK4 is a semi-automatic AR pistol chambered in 338 ARC with a 10.5-inch threaded barrel and a 10-round capacity. It has a black finish in a compact AR pistol configuration. 
 

Key Specifications 

• Brand: CMMG 
• Model: Banshee MK4 
• Caliber: 338 ARC 
• Action: Semi Auto 
• Capacity: 10+1 
• Barrel Length: 10.5 in 
• Color/Finish: Black 
   

Detailed Features 

• 10.5-inch threaded barrel 
• AR pistol configuration 
• Black finish 
• 10-round magazine capacity

The Banshee MK4 in 338 ARC occupies a narrow segment, and most sentiment around this variant is extrapolated from the broader Banshee line. The 338 ARC chambering is an uncommon choice and ammunition availability is the most cited concern among buyers researching this configuration.

The 10.5-inch AR pistol format gets generally positive marks for compactness. Build quality is a consistent point of praise across the Banshee line. The threaded barrel is appreciated by owners planning to add a muzzle device, and the 10-round capacity fits the format without drawing objection from most buyers.

The Banshee MK4 sits at a premium price point compared to entry-level AR pistols, which polarizes opinions. Those who chose 338 ARC specifically tend to be buyers who researched the chambering and committed to it. Long-term reliability data for this caliber variant is limited compared to higher-volume CMMG SKUs.