This MRP caliber conversion system allows for quick caliber changing between 5.56x45, .300blk, and .224 Valkyrie. The installation process is as easy as turning a couple retaining bolts with the LMT torque wrench. These barrels are made for the LMT CQB/MRP Monolithic receiver. They will not fit MWS receivers.

LMT’s quality engineering is well respected in the industry, and their barrels are no exception. Chrome lined and cryogenically treated, this barrel has all the durability-enhancing features that one would expect from a high-grade carbine. Combine incredible durability with LMT’s reputation for accuracy, and you have a versatile duty rifle that can keep up in any environment.

The gas system has already been installed to match your MRP upper receiver. To install this barrel, use the factory torque wrench to release the retaining bolts at the base of your handguard, swap this barrel in, and tighten the bolts down to LMT’s spec. If you want to change calibers or barrel lengths, we offer several other MRP barrels to match your needs.

Comes with an A2 birdcage flash hider pre-installed!

300 BLK 10.5":

(This barrel will not fit a full-size MRP receiver. This barrel is designed for MRP CQB receivers only.)

• 10.5” .300blk Barrel for LMT MRP CQB
• 1:7” RH Twist Rate
• Chrome-Lined
• Cryogenically Treated
• A2 Flash Hider Included

5.56 NATO 11.5": 

(This barrel will not fit a full-size MRP receiver. This barrel is designed for MRP CQB receivers only.)

• 11.5” 5.56 Barrel for LMT MRP CQB
• 1:7” RH Twist Rate
• Chrome-Lined
• Cryogenically Treated
• A2 Flash Hider Included

5.56x45 16":

(This barrel is made for the LMT CQB/MRP Monolithic receiver. It will not fit MWS receivers.)

• 16” Chrome-lined 1:7” RH Barrel for MRP or MRP CQB Monolithic Upper Receivers
• 5.56x45 Caliber
• Cryogenically treated for maximum durability
• Low profile gas block
• Mid Length straight gas tube
• A2 Birdcage Pre-Installed

5.56x45 20":

• Manufactured by Lewis Machine and Tool
• For LMT Monolithic Upper Receiver
• 5.56mm
• 20-inch barrel
• 41V50 chrome moly vanadium steel barrel, chrome lined 
• 1:7” RH twist barrel
• Cryogenically treated for maximum durability
• A2 birdcage flash hider
• Low profile gas block
• Mid-length straight gas tube
• Direct impingement