LMT Defense - AR-15 Barrel 8.25" 300 Blackout - L7BX1B

The LMT Defense AR-15 8.25" .300 Blackout MRP-L Barrel (L7BX1B) is LMT's most compact .300 Blackout barrel assembly, designed for ultra-short SBR, AR pistol, and suppressed builds on the LMT MRP-L upper receiver platform. At just 8.25", this barrel is optimized for .300 BLK performance in a PDW-sized package, offering excellent ballistics with both supersonic and subsonic .300 BLK ammunition. The pistol-length gas system is ideally tuned for use with suppressed and unsuppressed configurations. Machined from mil-spec chromoly steel with LMT's precision rifling at a 1:7" twist rate to stabilize the full range of .300 BLK projectiles.

• Part Number: L7BX1B
• Platform: LMT MRP-L (AR-15 light upper receivers)
• Caliber: .300 Blackout (.300 BLK / 300 AAC Blackout)
• Barrel Length: 8.25"
• Rifling Twist Rate: 1:7" RH
• Barrel Material: Chromoly steel
• Gas System: Pistol-length
• Operating Method: Direct impingement
• Compatibility: LMT MRP-L upper receiver chassis (L7NX1A 7.25" chassis recommended)
• Muzzle Threading: 5/8x24 TPI (standard .30 cal thread pitch)
• Manufacturer: Lewis Machine & Tool (LMT Defense), Milan, Illinois, USA

Ideal for suppressed .300 BLK builds, AR pistols, or PDW-style SBRs. Compatible with standard .308/7.62 bolt face AR-15 bolt carrier groups. Barrel only — BCG and upper receiver sold separately. This product may require an SBR/NFA tax stamp depending on your intended configuration. Consult applicable federal and state regulations.