The Dark Mountain Arms Stowaway is a bolt-action single-shot pistol chambered in 5.7x28mm with a 5.1-inch threaded barrel. It is a takedown design with a Picatinny/1913 rear brace adapter. The Stowaway holds 1 round and is finished in black. 
 

Key Specifications 

• Brand: Dark Mountain Arms 
• Model: Stowaway 
• Caliber: 5.7x28mm 
• Action: Bolt Action 
• Capacity: 1 Round 
• Barrel Length: 5.1 inches 
• Color/Finish: Black 
   

Detailed Features 

• 5.1-inch threaded barrel 
• Single-shot bolt-action operation 
• Takedown design 
• Picatinny/1913 rear brace adapter 
• 1-round capacity

The Stowaway attracts a niche buyer: someone who wants an ultra-compact 5.7x28mm platform in a takedown configuration. Owners cite the threaded barrel and brace adapter as practical features for a suppressed or braced setup, and the takedown form factor gets consistent praise for packability.

The single-shot bolt-action format is the most divisive aspect. Owners who use it as a trail gun or range curiosity are fine with the design intent, but buyers who expected faster follow-up shots are often surprised by the manual operation. The 5.7x28 chambering in a pistol barrel does not deliver the same velocity as a longer-barreled platform, which some owners note after purchase.

Dark Mountain Arms is a small manufacturer and aftermarket support is limited. Fit and finish reports are mostly positive on production examples, though some buyers note tight tolerances on takedown reassembly requiring a short break-in period.