Diamondback 300 Blackout 8.5" Pistol-Length Nitride 4150 CMV Steel Barrel - OEM Replacement

The Diamondback 300 Blackout 8.5" pistol-length nitride barrel is a direct OEM replacement barrel engineered for AR pistols and short-stroke builds running subsonic or supersonic rounds. Built from 4150 Chrome Moly Vanadium steel and finished in durable nitride coating, this barrel brings Diamondback's reputation for reliability to your next upper receiver—whether you're assembling a new pistol or swapping out a worn tube on an existing rifle.

The 8.5" length puts you in that sweet spot for 300 Blackout ballistics while keeping your platform compact and maneuverable. The nitride finish resists corrosion and wear, making it reliable through years of regular shooting, cleaning, and storage. As a Diamondback OEM part, it's designed to spec with Diamondback upper receivers and compatible with standard AR components, so you're not hunting for adapters or workarounds.

This is a straightforward parts replacement—no guessing, no surprises. Grab it when you need a reliable spare barrel or are building out a new upper, and you'll have the confidence that comes with a proven manufacturer's spec.

Key Features

• 8.5" pistol-length barrel optimized for 300 Blackout subsonic and supersonic loads
• 4150 Chrome Moly Vanadium steel construction for durability and longevity
• Black nitride finish resists corrosion and wear
• Diamondback OEM part—direct replacement for compatible uppers
• Designed for AR pistol and short-stroke rifle builds

Specifications

Frequently Asked Questions

Will this barrel fit my Diamondback upper receiver?

Yes—this is a Diamondback OEM replacement barrel, so it's manufactured to spec for Diamondback upper receivers. It will work with standard AR barrel extensions and components.

What's the difference between 300 Blackout in an 8.5" barrel versus longer barrels?

The 8.5" length is ideal for pistol builds and gives you a compact platform while still supporting both subsonic and supersonic 300 Blackout ammunition. Shorter barrels sacrifice some velocity compared to rifle-length barrels, but offer better handling and maneuverability in close-quarters applications.

Does nitride finish require special maintenance?

No. Nitride is a tough, corrosion-resistant finish that requires standard AR barrel care—clean, dry storage and normal maintenance. It doesn't need additional coating or special treatment.

Can I use this barrel as a direct replacement for a worn barrel?

Yes, it's designed as an OEM replacement. As long as you're working with a compatible Diamondback upper or a standard AR upper with appropriate dimensions, barrel swap procedures are straightforward.