LMT MRP Complete Upper

The LMT Monolithic Rail Platform (MRP) represents one of the most innovative upper receiver designs in the AR-15 market. Machined from a single 7075 T6 aircraft aluminum forging, the MRP creates a true monolithic structure where the upper receiver and rail system form one continuous piece. This construction method eliminates the traditional barrel nut and provides unmatched rigidity for enhanced accuracy potential and complete zero retention for any accessory mounted to the integrated Mil-Std 1913 rails.

The defining feature of the MRP is its patented quick-change barrel system. Unlike traditional AR-15 uppers requiring significant disassembly and specialized tools for barrel changes, the MRP barrel can be swapped in minutes using only a standard T-30 Torx bit. Two easily accessible locking bolts on the right side secure the barrel assembly, making caliber conversions or barrel length changes remarkably simple. This system is particularly valuable for users who need to adapt their platform for different missions or maintain multiple barrel configurations.

Available in both QUAD rail and M-LOK configurations, the MRP provides four solid Mil-Std 1913 rails (QUAD version) or modern M-LOK attachment points throughout. Multiple receiver lengths accommodate different barrel configurations, with the MRP-L QUAD 9.25 designed for 10.5" to 18" barrels and the MRP-L QUAD 13.25 for 14.5" to 20" barrels. The monolithic construction, combined with LMT's exacting manufacturing standards, makes this upper a favorite among precision shooters and professional users requiring the ultimate in modularity and reliability.