Diamondback Firearms DB15 Obsi 5.56 NATO Semi-Auto Rifle, 16″ Barrel, DB1784K791

Product Description

The Diamondback Firearms DB15 Obsi is a 5.56 NATO semi-auto rifle with a 16″ 4150 chrome moly barrel. It wears a Jungle Green Cerakote finish and measures 33″ overall. Capacity is 30+1 rounds, fed from a polymer AR-style magazine.

This rifle runs on a direct impingement system with a carbine-length gas system. The barrel has a 1:8″ twist and is threaded, and it carries an Obsidian muzzle device. You also get a forward assist and a dust cover. Up top is an A3 flattop receiver for mounting an optic. The rifle has no sights, so you will need to add your own. Furniture is a Magpul CTR stock and a Magpul MOE K2 grip, and the rifle has a manual safety.

Who it suits

The DB15 Obsi fits shooters who want a standard-pattern AR carbine and prefer to choose their own sighting setup. It works for range days, practice and general carbine use. It also makes a good base for a custom build.

Plan on a red dot or a low-power scope for the flattop, plus a set of backup iron sights if you want them. A sling, extra AR-style magazines and a padded rifle case round out the basics. The threaded barrel accepts muzzle devices, so check your local laws before adding one.

Diamondback Firearms DB15 Obsi 5.56 NATO Semi-Auto Rifle, 16" Barrel, DB1784K791 Specifications

What’s in the Box

1 Magazine (per the manufacturer’s listing).

Fits and Pairs With

• Winchester Repeating Arms M193 5.56 NATO 55 gr Ammo, 150 Rounds
• PMC Ammunition M855 Green Tip 5.56 NATO 62 gr Ammo, 840 Rounds
• Winchester Repeating Arms M193 Full Metal Jacket 5.56 NATO, 200 Rounds
• Winchester Repeating Arms M855 5.56 NATO 62 gr Ammo, 200 Rounds

Ordering from Western Sport

Order online and we ship it to the licensed FFL dealer you choose near you — see how buying a gun online works. Western Sport has been a licensed FFL/SOT dealer since 2007, and everything we sell carries the full manufacturer warranty. Questions before you order? Send us a message.

Frequently Asked Questions

Q: What caliber is the Diamondback DB15 Obsi?

A: 5.56 NATO. It is a semi-auto rifle with a 16" barrel and a 1:8" twist.

Q: Does the DB15 Obsi come with sights?

A: No. It has no sights, but the A3 flattop receiver lets you mount an optic of your choice.

Q: Is the DB15 Obsi barrel threaded?

A: Yes. The 16" barrel is threaded and carries an Obsidian muzzle device.

Q: What operating system does the DB15 Obsi use?

A: Direct impingement with a carbine gas system. It also has a forward assist and a dust cover.

Q: How many rounds does the DB15 Obsi hold?

A: 30+1 rounds. It uses a polymer AR-style magazine.

Warranty and Manufacturer

Covered by the Diamondback Firearms factory warranty; warranty terms come from Diamondback Firearms.

Additional information