Dark Mountain Arms Stowaway — 9mm, 5-inch Threaded
About this product
What is the Dark Mountain Arms Stowaway 9mm pistol? It is a large-format, bolt-action, single-shot pistol engineered for modular, precision-controlled shooting, with a removable 5-inch threaded barrel and a dedicated optics-ready Picatinny rail. This configuration is designed for disciplined marksmen who require a platform that adapts to specific tasks or compact storage scenarios, not for high-capacity defensive use. As a Title I firearm, it ships ready to accept optics and suppressors but requires a full Form 1/Form 4 regulatory process to use as a short-barreled rifle (SBR) or with a sound suppressor at the federal level.
What is the Dark Mountain Arms Stowaway used for?
This pistol is used for bench-rested subsonic ammo testing, introductory suppressor familiarization training, and as a highly compact, deliberate-practice tool. Its single-shot, bolt-action design forces a slow, methodical firing cadence ideal for analyzing load data or practicing fundamentals away from a full-size range. The removable barrel allows it to be broken down for discreet storage in a 13-inch hard case, a feature that sets it apart from fixed-platform training pistols.
How does the Dark Mountain Arms Stowaway compare to a Stevens 334 rifle?
The Stowaway pistol offers a more specialized, compact, and transport-oriented platform than a Stevens 334 Rifle. A Stevens 334 in .308 Win with a 20-inch barrel is better for true rifle-caliber hunting at distances beyond 50 yards, while the Stowaway excels as a dedicated, low-recoil suppressor host for 9mm at close range. The Stevens platform is a full-power repeater rifle; the Stowaway is a single-shot pistol focused on mechanical simplicity and the ability to be converted to another caliber with a bolt-face and barrel swap.
What does it weigh and what are the dimensions?
The Dark Mountain Arms Stowaway weighs 42 ounces (1.19 kg) unloaded and measures 19 inches in overall length with the barrel installed. In its stowed configuration with the barrel removed, the main assembly is 12.5 inches long and fits in a compact 13-inch hard case. The 5-inch cold-hammer-forged steel barrel has a 1:10 twist rate and is threaded 1/2x28 TPI for direct suppressor attachment.
Who is this NOT for?
This pistol is not for any user seeking a defensive or sporting firearm for rapid follow-up shots. Its single-shot, manual-cocking bolt action makes it unsuitable for practical pistol competition, home defense, or hunting moving game. If your primary need is a multi-round repeating action, consider a more conventional bolt-action rifle like the Stevens 334 instead.
What's in the box?
The box includes the Stowaway pistol assembly, the 5-inch 9mm threaded barrel, a Picatinny rail section pre-installed with Torx fasteners, one 9mm bolt head, and a manufacturer's compliance manual. Notably, it does not include any optics, a case, thread protector, or a suppressor piston—those are owner-supplied components critical for the platform's intended role.
Is the Dark Mountain Arms Stowaway worth it at $407?
At $407, it is worth it for a very specific shooter who values its unique, modular, suppressor-ready design for niche applications. You are not paying for firepower but for a precision-machined, adaptable single-shot platform built for testing and trainer use. Compared to building a custom 9mm bolt-action from a rifle receiver set, the Stowaway offers a ready-made, dedicated solution that saves considerable gunsmithing time and expense, provided its deliberate-fire limitations align with your goals.
Specs at a glance
Video review
Pros & cons
What works
- Weighs 42 oz (1.19 kg) — balances well with a suppressor attached
- Removable 5-inch barrel reduces transport length to 12.5 inches for a 13-inch case
- No proprietary optic mounting — uses standard Picatinny rail for direct red-dot attachment
Trade-offs
- Single-shot only — no magazine compatibility or repeat-fire capability
- Requires separate purchase of a fixed-barrel adapter for most 9mm suppressors (adds $50-$120)
- No iron sights pre-installed — necessitates an immediate optics purchase of at least $150
Expert review
Key attributes
| upc | 850061930033 |
| manufacturer | Dark Mountain Arms LLC |
| manufacturer part number | SA-121 |
| barrel length | 5" |
| caliber/gauge | 9mm |
| capacity | 1 |
| shipping weight | 3.3 |
Frequently asked questions
- Is it compatible with a Glock 19 suppressor?
- Yes, with the correct adapter. The 1/2x28 threaded muzzle is a direct industry standard. However, many 9mm suppressors use a piston system for tilt-barrel pistols; since the Stowaway has a fixed barrel, you will need a fixed barrel spacer or a dedicated fixed-mount adapter from your suppressor manufacturer like SilencerCo or Dead Air.
- Does it fit in a standard pistol case?
- No, not in its assembled form. Assembled, it is 19 inches long, exceeding typical handgun case dimensions. For transport, you must remove the barrel, reducing its length to 12.5 inches. It then fits securely in a compact 13-inch hard case, like a Pelican 1170, which is a separate purchase.
- How long does assembly take after purchase?
- From box to range-ready, expect 15-20 minutes for a basic setup. This includes mounting an optic, securing the barrel with the supplied wrench, and performing a function check. If adding a suppressor, factor in additional time to ensure proper thread alignment and torque, which is a critical 5-10 minute step to prevent baffle strikes.
- Can I convert it to .22 LR?
- Potentially, but not directly. Converting requires a proprietary bolt head and barrel assembly specific to .22 LR, which must be sourced from Dark Mountain Arms. This is not a simple barrel swap like on a T/C Encore; it involves changing both the bolt face and the barrel, a process requiring manufacturer-specific parts and technical familiarity.