Diamondback DB15 .300 AAC Blackout 16 in 15 in M-LOK FDE 30rd
About this product
The Diamondback DB15 in .300 AAC Blackout is a direct gas impingement, semi-automatic rifle with a 16-inch barrel built on a forged 7075-T6 aluminum upper receiver. It's designed as a mid-tier AR-platform weapon that bridges the gap between budget-friendly pistols and high-end rifles like Daniel Defense. This specific configuration, with its 15-inch M-LOK handguard and Flat Dark Earth finish, is optimized for suppressor use and modular accessory mounting without the NFA paperwork of an SBR.
What is the Diamondback DB15 .300 Blackout used for?
This rifle is primarily a suppressor host and a mid-range hunting platform for game up to white-tailed deer. The .300 AAC Blackout cartridge is engineered to burn all powder within a 9-inch barrel, making a 16-inch barrel like this exceptionally quiet when paired with a quality can, with sound reduction easily reaching 35 decibels. It's also a capable home defense tool, though over-penetration in drywall is a legitimate concern compared to 5.56 NATO frangible rounds.
How does the Diamondback DB15 compare to the Stevens 334 Rifle?
The Diamondback DB15 offers faster follow-up shots and greater modularity than a bolt-action rifle like the Stevens 334 in .308 Win, but with less inherent long-range precision. For a hunter needing two quick shots in thick brush at 150 yards, the DB15 is superior. For a precision shooter demanding sub-MOA groups at 300+ yards, the Stevens 334 platform is the objectively better tool, sacrificing rate of fire for mechanical lockup and a fixed barrel.
What does it weigh and what are the dimensions?
Unloaded, with no optic or accessories, this rifle weighs 6.8 pounds. The overall length from the end of the threaded muzzle to the rear of the buffer tube is 35.5 inches. The 15-inch handguard provides 13.75 inches of continuous Picatinny rail at the 12 o'clock position and M-LOK slots at the 3, 6, and 9 o'clock positions for mounting lights, grips, and bipods without adding significant width.
Who is this NOT for?
This rifle is a poor choice for a first-time buyer on a strict budget who just wants to plink with cheap ammo. .300 Blackout ammunition costs nearly double that of 5.56 NATO, turning a range day into a significant expense. It's also not for the shooter unwilling to invest in a suppressor; without one, you're paying a premium for a cartridge's primary benefit you aren't using, and you'd be better served by a standard 5.56 AR-15.
What's in the box?
You receive the complete rifle, one 30-round Magpul PMAG, and a basic operator's manual. Unlike some competitors, Diamondback does not include a rear sight, a sling, or a cleaning kit. Planning for those additions—approximately $60 for a basic MBUS rear sight and $40 for a USGI sling—is part of the true cost of making this rifle range-ready.
Is the Diamondback DB15 worth it at $700.99?
At just over seven hundred dollars, it represents competent value for a dedicated .300 Blackout host, but only if you already own a suppressor or have one in the ATF's approval pipeline. The forged upper, carbine-length gas system, and nitride-treated barrel are solid for the price point. However, if suppressed shooting isn't your immediate goal, a Stevens 555 Sporting shotgun offers more versatility for less money, and a 5.56 AR-15 offers drastically cheaper practice.
Specs at a glance
Video review
Pros & cons
What works
- Forged 7075-T6 aluminum upper - provides a rigid platform superior to cast or billet receivers for durability at this price point.
- 15-inch M-LOK handguard - offers 13.75 inches of unobstructed rail space for forward grips, lights, and laser modules.
- 1:8 twist rate barrel - correctly stabilizes the full spectrum of .300 BLK rounds from 110-grain supersonic to 220-grain subsonic.
- Threaded 5/8-24 muzzle - ready for a direct-thread suppressor or muzzle device without additional gunsmithing.
Trade-offs
- No iron sights included - adds a minimum of $80 to the true cost for a basic set of MBUS Gen 2 sights to make it functional.
- Proprietary aluminum/carbon fiber lower - limits aftermarket stock and trigger guard compatibility compared to a mil-spec forged lower.
- Carbine-length gas system on a 16-inch barrel - can be over-gassed with hot loads, increasing wear and felt recoil compared to a mid-length system.
Expert review
Key attributes
| upc | 810035756458 |
| manufacturer | Diamondback Firearms |
| manufacturer part number | DB1718B062 |
| action | Semi-Auto |
| atf type | RIFLE |
| barrel length | 16" |
| caliber/gauge | .300 AAC Blackout |
| capacity | 30 + 1 |
| color | Flat Dark Earth |
| number of magazines | 1 30 rd. |
| package height | 4.0 |
| package width | 9.0 |
| product type | Rifle |
| shipping weight | 8.1 |
Frequently asked questions
- Is it compatible with standard AR-15 parts?
- Yes, the upper and lower receivers use mil-spec dimensions. You can swap the trigger, grip, stock, and handguard with any standard AR-15 component. The bolt carrier group is a standard .300 Blackout type, which is dimensionally identical to a 5.56 BCG but should not be interchanged due to safety concerns.
- Does this work with a 5.56 NATO suppressor?
- No, you must use a .30 caliber rated suppressor. A 5.56 can is not rated for the .308 diameter bullet of the .300 Blackout and presents a serious safety risk. Popular compatible models include the SilencerCo Omega 300 and Dead Air Sandman-S, which use the standard 5/8-24 thread pitch on this barrel.
- How long does shipping take?
- Most orders ship within 2 business days following FFL verification. Transit time via ground carrier averages 3-5 business days to the continental US. You must provide your chosen FFL's contact information at checkout to prevent delays. We cannot ship directly to a residential address.
- Can I return it if I don't like it?
- Unfired firearms in original packaging can be returned within 30 days, subject to a 15% restocking fee and the cost of return shipping to our warehouse. Once the firearm has been fired, it is considered used and is not eligible for return unless there is a verifiable manufacturer defect, which must be documented within 72 hours of receipt.
- Will it cycle subsonic ammunition without a suppressor?
- Maybe, but it's not guaranteed. The carbine-length gas system is tuned for supersonic loads. Running heavy 220-grain subsonics without the backpressure from a suppressor often leads to short-stroking and failure to eject. For reliable subsonic use, plan on installing an adjustable gas block, a $75-$120 part plus gunsmithing.