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Diamondback
Overview
The Diamondback Firearms .300 Blackout AR-15 Barrel is an 8.5" heavy profile barrel designed specifically for the .300 Blackout caliber, making it an excellent choice for compact builds that prioritize maneuverability without sacrificing performance. With a pistol-length gas system and a 1:8 twist rate, this barrel is optimized for stability and accuracy, effectively stabilizing a range of bullet weights while providing reliable cycling in short-barreled applications. This barrel commonly appears in builds focused on tactical or close-quarters configurations where a short, powerful platform is desired.
Specifications
Diamondback Firearms .300 Blackout AR-15 Barrel Nitride - 8.5"
Available Merchants(4)
Prices checked
Stock Alert
October 2026 on GunPartPicker
Diamondback Firearms .300 Blackout AR-15 Barrel Nitride - 8.5" ranked #131 of the 329 barrels builders added on GunPartPicker in October 2026. Builders have added it to their builds on GunPartPicker. Since April 2026, it ranks #198 of the 1,043 barrels builders have added. Builds with this barrel are nearly all chambered in 300 Blackout, nearly all on pistol-length gas, and nearly all AR-15.
Availability is good: it was in stock at one retailer or another nearly every time we checked in October 2026, but today none of the 4 retailers we track has it in stock right now. Prices barely moved in October 2026, holding around $72.99, with no real sale all month. Listed prices start at $72 at BattleHawk Armory for when it comes back.
Updated · from real builds on GunPartPicker · Prices checked · refreshed daily across 37 retailers
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Frequently Built With
The part most often added in each category by the builds that include this one
Aero Precision M4E1 Stripped AR-15 Lower Receiver - FDE Cerakote
Aero Precision AR-15 Stripped Upper Receiver, No Forward Assist Black
Rise Armament Super Sporting AR15/10 Single Stage Trigger - Flat - Dtom Special Edition
Strike Industries T-Bone AR-15 Charging Handle for .223/5.56 - Black/Black
Tacfire's 7" ACE M-LOK Handguard for AR-15 - Black, Balance and Versatility in One - HG20-7
PSA AR-15 Bolt Carrier Group 5.56 Full-Auto Nitride MPI - 516446953
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