Why consider the Diamondback Obsidian Pistol? Over the years, I’ve handled my fair share of AR-platform rifles, from off-the-shelf budget models to custom builds assembled with match-grade parts, and very few strike that perfect balance between performance, build quality, and sheer handling enjoyment. 

This one does. I’m not saying it’s perfect, because no gun is. But there’s something deeply satisfying about a rifle that feels right the first time you shoulder it. Wait, did I say “shoulder” it? I meant “brace” it. (Sorry, ATF AI bot agents snooping the interwebs, looking for inadvertent violations. You won’t find any here.)

Before we get into the gun, let’s answer the question of why they call it ‘Obsidian.’ As Shakespeare famously asked in Romeo & Juliet, what’s in a name? Obsidian is a volcanic glass rock that is both strong and durable. Ancient civilizations used it as a cutting tool—and a weapon. It served well as a tip of a spear or a knife. That warrior tradition carries over into a rifle that, like a spear, can reach out and touch someone in a special way.

First Impressions & Build Quality

The Diamondback Obsidian Pistol isn’t just another black rifle. First of all, it’s green, but there’s more to it than that. It has a sleek, understated tone that strikes a balance between military aesthetics and civilian utility. The Cerakote job appears flawless, boasting a durable, matte texture that doesn’t glare or smudge. Underneath the finish is a 7075-T6 aluminum receiver set, machined in-house by Diamondback in Cocoa, Florida.

The 11.5-inch barrel immediately caught my attention. It’s the perfect sweet spot for an SBR-style rifle or pistol, giving enough compactness to maneuver easily indoors (ideal for home defense) while maintaining solid ballistic performance from the 5.56 or .223 round. The Obsidian features a black nitride-coated barrel, enhancing durability and corrosion resistance. That coating also gives it a clean, dark finish that visually aligns with the rest of the rifle.

From the first inspection to the hundredth round downrange, this gun impressed me. It’s lightweight but sturdy, tactical without being overbuilt, and compact enough to feel at home anywhere, from a truck rack to a home defense setup. 

That “built in Florida” tag means something here. The machining is tight, the tolerances feel deliberate, and nothing wiggles or rattles. The upper and lower fit cleanly without the annoying play that sometimes occurs in lower-tier ARs. Even before firing a round, this gun gave me confidence. After several magazines, that feeling held.

Diamondback Obsidian Pistol: Handling & Ergonomics

Compact ARs sometimes have trade-offs in balance and controllability, but not in this case. The DB15 Obsidian’s design is tight and compact without being front-heavy. The full-length 10-inch M-LOK handguard provides ample real estate for accessories like pop-up sights and an optic.

The slim (but not overly slim) handguard allows for easy thumb-over-bore control. With a good two-point sling, I could easily switch between low-ready and aimed fire. The DB15’s geometry makes transitions between targets intuitive. In close quarters, this rifle shines, thanks to the relatively stubby barrel that works easily in hallways and other tight confines.

The pistol grip is one of those often-overlooked features, but Diamondback got it right. It’s textured enough for solid control without tearing up your hand after 200 rounds. The grip angle feels natural whether shooting from the shoulder or low ready.

The barrel cap is a DB Obsidian Muzzle Brake, standard and functional. It does an admirable job of keeping flash minimal without overcomplicating the package.

The Diamondback Obsidian Pistol’s Range Performance

My first range outing with the DB15 Obsidian was a classic eastern Missouri fall afternoon: cool air, mild wind, perfect light. I stabbed two targets into the ground: one at 50 yards, the other at 100. Since this is a shorter-barreled gun, I didn’t feel the need to go too far out, as this gun really isn’t for sniping. It’s definitely more suited for closer-range engagements.

The gun’s 11.5-inch barrel gives it some snap, but recoil is remarkably mild. The Diamondback Obsidian pistol’s carbine-length gas system feels well-tuned, with ejection patterns consistently around the 3 o’clock position. That reliable cycling held across several different brands and grains, including Winchester, Sellier & Bellot, and Black Hills.

When running controlled pairs and rapid strings, muzzle rise remained minimal. The rifle stayed flat, predictable, and responsive. Even unsupported, double- and triple-taps stayed tight. For drills like failure-to-stop or target transitions at close range, the DB15 handled like a lightweight sports car: agile and responsive.

A shorter barrel obviously sacrifices some velocity compared to a full 16-inch setup. Still, for most civilian applications, including home defense, vehicle transport, or range fun, the trade-off is well worth it.

The Diamondback Obsidian Pistol’s Accuracy & Reliability

With all the rounds I put down the barrel, the Obsidian performed flawlessly, with no malfunctions or other mechanical issues. The bolt carrier group looks properly staked, and the nitride finish on both the bolt and carrier makes cleaning smooth and easy. Even after long shooting strings, carbon buildup was manageable, and cycling stayed smooth.

The ambidextrous short-throw safety selector stayed crisp, the charging handle operated smoothly, and no parts showed unusual wear. I didn’t expect this added-value touch on a lower-priced AR.

Key Features & Benefits

• Barrel: 11.5-inch 4150 Chrome-Moly with black nitride finish for durability and corrosion resistance
• Receiver Set: 7075-T6 aluminum, CNC-machined in-house for precise tolerances
• Handguard: 10-inch free-float M-LOK compatible aluminum rail with a slim, comfortable profile
• Magazine Catch: Battle Arms ambi magazine catch, a pleasant surprise on a budget AR
• Brace and Grip: Collapsible SB Tactical SBA5 brace (to keep it off the SBR NFA list) and ergonomic polymer Magpul MOE K2 grip for flexible control
• Trigger: Standard single-stage mil-spec trigger (easily upgradeable)
• Finish: OD Green Cerakote, durable and understated
• Made in the USA: Manufactured and assembled in Cocoa, Florida

 Use Cases and Practical Value

For home defense, the 11.5-inch barrel is about as compact as you can get without an SBR tax stamp, provided you’re running it as a pistol configuration or under proper registration. (Dang ATF.) Maneuvering through tight hallways or around furniture is noticeably easier than with a standard 16-inch barrel. Add a light and red dot, and you’ve got a highly capable defensive tool.

On the range, it’s fun, accurate, and controllable enough for newer shooters to enjoy without being intimidating. My kids, who are experienced shooters but still young, loved running it.

Its compact form factor, ideal for truck or field carry, makes it a go-to companion for these applications.

Upgradability & Customization

As with most ARs, Diamondback’s Obsidian series leaves plenty of room for users to make the rifle their own. Notice I didn’t say “improvements.” Not that you can’t upgrade things, but the out-of-the-box configuration is solid.

The M-LOK handguard offers freedom for attaching various accessories, including vertical grips, bipods, lasers, and offset optics. The upper’s Picatinny top rail extends full length, ideal for mounting optics alongside backup sights. I added a Mepro Tru-Vision rifle red dot after swapping out the black case for the OD green housing.

The mil-spec trigger is serviceable but not spectacular. After a few rounds, I got used to it, though I’d likely replace it with something fancier for quicker reset and lighter pull. The factory trigger is absurdly loud during dry fire, especially the reset. My son sarcastically commented that the trigger reset was almost as loud as firing the gun with a suppressor. He’s not far off. This is definitely not the first choice of ARs for ninjas.

Internals like the bolt carrier group and gas system feel rock solid, with no need for upgrades unless you’re chasing top-tier precision builds.

Diamondback includes the SB Tactical SBA5 Brace as the standard setup, preventing the need for the ATF to get their panties in a bunch over a stock. If you choose to swap it out for a stock, remember that could make you a felon, because that simple swap makes it an SBR.

The grip is the excellent Magpul MOE K2 Grip, a common AR grip that has found its way onto many an AR platform because it’s comfortable and has a handy little hidden compartment for gun oil or, if you’re so inclined, a mid-range-day granola bar.

Maintenance & Longevity

Cleaning and maintenance were refreshingly straightforward, nothing out of the ordinary for an AR platform. The bolt carrier group breaks down easily, and the nitride coating makes carbon removal far less laborious. The Cerakote has held up well against oil, grime, and a few bumps on the range.

Granted, I haven’t had the gun very long (barely two months at the time of this writing), but there is no sign of wear from my limited time with it. With a good cleaning, it looks brand new, and I have no reason to think that would change. Diamondback is a reputable brand with no major complaints that I’m aware of. They are not a high-end custom shop, but the Obsidian seems to be a solid build with no apparent flaws. Perhaps if I spend more time behind the gun, flaws will emerge, but so far, none have.

The gun ships with one Magpul 30-round magazine, for those who live in freedom-loving states, smaller mags for those who are stuck in anti-gun hell. A second magazine would be nice, but this is a budget-friendly gun, and AR magazines are cheap and plentiful, so finding more won’t be a problem.

Parting Shots: Diamondback Obsidian Pistol

Priced at a modest $1,200 and some change MSRP, the Diamondback DB15 11.5” Obsidian Series in OD Green shows what a modern, American-made AR-15 pistol can be when designed by a company that knows its craft. It’s not trying to reinvent the wheel but perfects the balance between quality, ergonomics, and practicality. If you’re looking for a compact 5.56 that blends tactical styling, reliability, and everyday usability, all proudly built in the USA, this rifle is worth a look.