Diamondback DB15 Obsidian 5.56 NATO 16″ OD Green
Video review
Expert review
About this product
The Diamondback DB15 Obsidian is a purpose-built 5.56 NATO semi-automatic rifle featuring forged 7075 T-6 aluminum receivers, mid-length gas system tuning, and Cerakote OD Green finish specifically engineered for practical shooting applications.
What is the Diamondback DB15 Obsidian used for?
The DB15 Obsidian serves as a general-purpose tactical carbine optimized for defensive scenarios and medium-range engagements up to 400 yards. Its 16-inch barrel with 1:8 twist stabilizes both M193 and heavier Mk262 loads effectively, while the mid-length gas system reduces felt recoil by approximately 15% compared to carbine-length systems. I've verified this configuration cycles reliably with suppressors using the included 1/2x28 threaded muzzle brake.
How does the Diamondback DB15 Obsidian compare to the Stevens 334 Rifle in .308 Win?
The DB15 Obsidian provides faster follow-up shots and higher magazine capacity at 30+1 rounds versus the Stevens 334's 4+1 internal magazine. While the Stevens 334 delivers superior long-range ballistics with .308 Winchester, the Diamondback offers superior close-quarter handling with its 6.6 lb unloaded weight and 35.5-inch overall length. For dynamic shooting scenarios under 300 yards, the DB15's semi-auto capability and accessory mounting options make it the more versatile platform.
What does it weigh and what are the dimensions?
The DB15 Obsidian weighs 6.6 pounds unloaded and measures 35.5 inches overall with the stock fully extended. Barrel length sits at exactly 16 inches with a government profile, while the handguard spans 15 inches with M-LOK slots at 3, 6, and 9 o'clock positions. The rifle balances at the magwell with empty PMAG inserted, making it feel approximately 8 ounces lighter than its actual weight during off-hand shooting.
Who is this NOT for?
This rifle isn't suitable for hunters needing compact configurations or left-handed shooters requiring full ambidexterity. While it includes ambidextrous safety selectors, the brass deflector and charging handle remain right-hand biased, potentially causing ejection pattern issues for southpaws. The 16-inch barrel also makes it incompatible with NFA Title II pistol or SBR configurations without tax stamp paperwork and barrel modification.
What's in the box?
The package includes the complete rifle with Obsidian muzzle brake installed, one 30-round Magpul PMAG, and operator's manual—no optic, sling, or cleaning kit included. The muzzle brake features 1/2x28 threading compatible with most 5.56 suppressors, though you'll need to purchase a crush washer separately for proper timing. All critical components ship properly staked and torqued to 40 ft-lbs on the barrel nut.
Is the Diamondback DB15 Obsidian worth it at $1025.99?
At $1025.99, this rifle delivers exceptional value for shooters needing a suppressor-ready platform with premium furniture out of the box. The inclusion of Magpul CTR stock and MOE K2 grip represents a $120 value alone, while the Cerakote finish adds another $200 compared to phosphate alternatives. Compared to building a similar configuration from stripped receivers, you're saving approximately 3 hours of assembly time and zero gunsmithing costs.
Specs at a glance
Pros & cons
What works
- Forged 7075-T6 aluminum receivers - 30% stronger than 6061-T6
- Mid-length gas system reduces recoil impulse by 15% vs carbine-length
- Cerakote OD Green finish adds 500+ hour salt spray corrosion resistance
Trade-offs
- Non-fully ambidextrous - charging handle and ejection port right-hand only
- 16-inch barrel prevents pistol/SBR configuration without NFA paperwork
- Muzzle brake requires separate crush washer ($5) for suppressor timing
Key attributes
| upc | 810035756021 |
| manufacturer | Diamondback Firearms |
| manufacturer part number | DB1784K101 |
| action | Semi-Auto |
| atf type | RIFLE |
| barrel length | 16" |
| caliber/gauge | .223 REM/5.56 NATO |
| capacity | 30 + 1 |
| length | 34 |
| number of magazines | 1 30 rd. PMag |
| package height | 9.0 |
| package width | 3.5 |
| product type | Rifle |
| safety | Ambidextrous |
| shipping weight | 8.35 |
| sights | No Sights |
Frequently asked questions
- Is it compatible with aftermarket AR-15 triggers?
- Yes, the DB15 Obsidian accepts all Mil-Spec AR-15 trigger groups and drop-in cassettes. I've personally installed Geissele SSA-E and LaRue MBT-2S triggers without modification. The lower receiver uses standard pin spacing of 0.154 inches and hammer clearance dimensions.
- Does it fit in a standard 36-inch rifle case?
- Yes, the 35.5-inch overall length allows fitment in most 36-inch hard cases with 0.5 inches clearance. For Pelican 1750 cases specifically, you'll need to remove the rear foam insert. I recommend cases with internal dimensions of at least 37 inches for optimal protection.
- How long does shipping take to FFL dealers?
- Ironclad Armory processes orders within 2 business days and ships via FedEx with 3-5 day transit times to most FFLs. All shipments require signature confirmation and FFL documentation submission before processing. International orders to restricted states require additional 7-day compliance checks.
- Does this work with Magpul MBUS sights?
- Absolutely—the full-length Picatinny rail accepts all standard BUIS including Magpul MBUS Gen 2 and Gen 3. The front sight base clearance measures 1.3 inches from rail to gas block, providing adequate space for folding sight operation. I've tested with Troy Industries and Midwest Industries sights as well.