Diamondback DB15 Obsidian Black – Superb 5.56 16 in. Rifle

Description

The Diamondback DB15 Obsidian Black is a fully equipped 5.56 AR-15 that ships with the upgrades most shooters end up buying anyway. It runs a 16 inch nitrided barrel on a mid-length gas system, a 15 inch free-floating M-LOK handguard, ambidextrous controls, the Obsidian muzzle brake, and Magpul furniture, and it comes with a 30 round PMAG.

Diamondback DB15 Obsidian Black Barrel and Brake

The barrel is 4150 chrome moly vanadium steel in a medium contour, black nitrided inside and out, with a 1:8 right hand twist. Nitride is a case hardening treatment rather than a surface coating, so it cannot flake or wear through, and it makes the bore noticeably easier to clean. The 1:8 twist covers the full useful range of 5.56 bullet weights, from 55 grain bulk ammunition to 77 grain match loads.

At the muzzle sits the Diamondback Obsidian brake on 1/2×28 threads, and it is the reason the model carries the name. It cuts muzzle rise enough that you can call your own shots through an optic without breaking position. Gas is mid-length rather than carbine, which gives the bolt more dwell time and a softer, more drawn-out impulse.

Handguard, Controls, and Furniture

The 15 inch M-LOK handguard uses an anti-rotation mount and carries a continuous Picatinny top rail that lines up with the upper receiver. It free floats the barrel, which helps accuracy, and it gives you M-LOK slots at several clock positions for lights, bipods and hand stops without adding rail weight you do not use.

Ambidextrous safety and magazine catch are standard, which is uncommon in this price bracket and makes a real difference for left handed shooters. The bolt carrier is mil-spec 8620, shot peened and magnetic particle inspected. Furniture is Magpul, a CTR stock and a K2 grip, and the whole rifle is finished in black.

Specifications

• Model: DB15 Obsidian
• Caliber: 5.56x45mm NATO, also accepts 223 Remington
• Action: Semi-automatic, direct impingement
• Capacity: 30+1, one Magpul PMAG included
• Barrel length: 16 in., medium contour, 4150 CrMoV, black nitride
• Twist rate: 1:8 right hand
• Gas system: Mid-length
• Muzzle: Diamondback Obsidian muzzle brake, 1/2×28 threads
• Handguard: 15 in. M-LOK, anti-rotation, full Picatinny top rail
• Bolt carrier: Mil-spec 8620, shot peened, magnetic particle inspected
• Controls: Ambidextrous safety selector and magazine catch
• Stock: Magpul CTR
• Grip: Magpul K2
• Finish: Black
• Weight: 6.6 lbs.
• Overall length: 33 in. collapsed to 36.25 in. extended
• Sights: None, optic ready
• UPC: 810035756007

Why Buyers Choose the Diamondback DB15 Obsidian Black

Value, mostly. Add up a mid-length gas system, a nitrided 4150 barrel, an effective muzzle brake, a 15 inch free-float M-LOK rail, ambidextrous controls, and Magpul furniture, and you have described a rifle that usually costs several hundred dollars more. Diamondback assembles it that way from the factory instead of leaving you a list of upgrades.

Black is also the practical choice for a working rifle. Accessories, spare parts, and replacement furniture are all easiest to match in black, and a black rifle never looks mismatched when you add a light, an optic mount, or a sling in whatever color you already own.

Who Should Buy It

First-time AR buyers who want to skip the upgrade cycle, left handed shooters who want ambidextrous controls without a premium billet lower, and anyone assembling a general-purpose 5.56 for the range, training, or home defense. It also works well as a hog and predator rifle with the right optic. If you want a match-grade trigger, plan on a drop-in unit, because this rifle ships with a standard mil-spec trigger.

Learn more from Diamondback Firearms, or browse the rest of our firearms selection.

Every firearm we list ships to your chosen FFL and is transferred there after a background check.