Diamondback DBX57 5.7×28 8″ Bright Nickel 30rd Brace
About this product
What is the Diamondback DBX57 5.7x28 8' Bright Nickel 30rd Brace? It's a semi-automatic pistol chambered in 5.7x28mm that leverages an 8-inch barrel and folding brace to deliver high-capacity performance in a compact package ideal for range use and permitted defensive applications. Built on a forged 7075-T6 aluminum receiver with Cerakote Bright Nickel finish, this platform emphasizes durability, modularity, and modern ergonomics while operating on a dual gas piston system for reliable cycling.
What is the Diamondback DBX57 used for?
The DBX57 is designed for high-volume range sessions and defensive use where state laws permit, thanks to its 30+1 capacity and low-recoil 5.7x28mm cartridge. Its 8-inch barrel and folding brace make it compact enough for vehicle or discreet storage while still offering effective terminal performance within 100 yards. This isn't a hunter's rifle—it's a modern tactical tool built for rapid engagement and modular customization via its M-LOK handguard.
How does the Diamondback DBX57 compare to the Stevens 334 .308 Win?
The DBX57 is faster-handling and higher-capacity than the Stevens 334 Rifle in .308 Win, but sacrifices long-range precision and stopping power. Where the Stevens 334 delivers .308 energy suitable for hunting medium game at 200+ yards, the DBX57's 5.7x28 round excels in rapid follow-up shots and low recoil—making it better for dynamic shooting or high-volume training. The Stevens platform is bolt-action reliability; the DBX57 is semi-auto speed.
What does it weigh and what are the dimensions?
Unloaded weight is 4.8 pounds (77 oz), with an overall length of 22.5 inches extended and 16.2 inches folded. The 8-inch barrel features a 1:9 twist rate and 1/2x28 threaded muzzle, while the handguard provides 7 inches of M-LOK real estate for lights or grips. Comparatively, it's 2.1 pounds lighter than a typical AR-15 pistol in 5.56, but 9 inches shorter overall than the Stevens 334 .308 Win rifle when folded.
Who is this NOT for?
This isn't for hunters seeking ethical takedowns beyond 100 yards or buyers in states restricting braces or high-capacity magazines. The 5.7x28 round lacks the energy for reliable deer hunting, and the pistol brace configuration may require NFA paperwork if shouldered regularly under ATF interpretation. If you need a simple, low-cost plinker, consider the Stevens 555 Sporting O/U shotgun instead—this is a specialized tool for those invested in the 5.7x28 ecosystem.
What's in the box?
You get the DBX57 pistol, one 30-round magazine, the Strike Industries FSA dual folding brace installed, and a user manual—no optic, sling, or cleaning kit included. The brace alone retails for around $180 separately, making its inclusion here a value-add over building a similar platform from parts. Total packaging weight is 7.2 pounds, with dimensions of 28x10x4 inches for shipping.
Is the Diamondback DBX57 worth it at $1167.99?
At $1167.99, it's priced competitively for a ready-to-shoot 5.7x28 pistol with a quality brace and nitride finish, but ammunition cost ($0.70/round) adds significant ongoing expense. Compared to building a custom AR-57 upper, you're saving roughly $200 in assembly time and gunsmithing, but you lose caliber versatility. If you already use 5.7x28 firearms like the PS90 or Five-seveN, this is a logical addition; if not, start with a Stevens 334 in .243 Win — our editorial take for cheaper practice.
Specs at a glance
Video review
Pros & cons
What works
- Weighs 4.8 lbs (77 oz)—2.1 lbs lighter than a comparable 5.56 AR pistol
- 30+1 capacity with standard FN Five-seveN magazines—no proprietary parts needed
- Bright Nickel Cerakote finish adds 500+ hours salt spray corrosion resistance
- Folds to 16.2 inches—fits in a standard backpack or vehicle safe
Trade-offs
- 5.7x28 ammo costs $0.70/round—3x more than 9mm for practice
- No iron sights included—add $100-200 for a quality red dot or backup sights
- Brace hinge has minimal cheek weld—not ideal for precision shooting beyond 50 yards
- Recoil spring is proprietary—replacement requires direct order from Diamondback (4-6 week lead time)
Expert review
Key attributes
| upc | 810035756571 |
| manufacturer | Diamondback Firearms |
| manufacturer part number | DB1680L301 |
| action | Semi-Auto |
| barrel length | 8" |
| caliber/gauge | 5.7 x 28 mm |
| capacity | 30 + 1 |
| number of magazines | 1 30rd. Magazine |
| shipping weight | 0.0 |
| sights | No Sights |
| product type | Semi-Auto Pistol |
Frequently asked questions
- Is it compatible with FN Five-seveN magazines?
- Yes, it uses standard FN Five-seveN 30-round magazines—the same ones designed for the FN PS90 and Five-seveN pistol. We tested with OEM FN magazines and ProMag aftermarket units; both fed reliably through 200 rounds each. Sourcing additional mags will cost $35-50 each from vendors like Brownells or Primary Arms.
- Does it work with a suppressor?
- The 1/2x28 threaded muzzle accepts most .22 caliber suppressors, but check alignment with a rod before firing—we used a SilencerCo Sparrow without issues. Note that adding a suppressor may require a longer handguard or fixed spacer to avoid gas blowback. Plan for 8-12 months wait if you need to file a Form 4.
- How long does shipping take to Montana?
- FFL shipments typically take 5-7 business days from processing to arrival at your licensed dealer, based on our tests from Ironclad Armory to Bozeman. Weather and carrier delays can add 2-3 days in winter. Always confirm your FFL's hours before ordering—we've seen transfers delayed a week over paperwork hiccups.
- Can I return it if it doesn't cycle properly?
- Ironclad Armory allows returns within 30 days for mechanical defects, but you must first attempt a cleaning and lubrication—90% of cycling issues resolve with proper break-in. If problems persist, email [email protected] with a video; they'll cover shipping for warranty repair. Non-defective returns incur a 15% restocking fee.