Mrp-H M-Lok 7.62Mm 12.5'' Assembled Upper Receiver

The LMT Defense MRP-H M-LOK 7.62mm 12.5" assembled upper receiver is a monolithic platform built for shooters who demand precision and durability in large-caliber rifle builds. This is one-piece construction—receiver and handguard machined from aerospace-grade aluminum—that eliminates the flex and slop common in two-piece designs. If you're building a 7.62×51 NATO, 6.5 Creedmoor, .260 Remington, or other supported caliber rifle and want a rock-solid foundation, this upper delivers the rigidity long-range and tactical applications require.

What sets the MRP-H apart is LMT's proprietary barrel-retention system: two locking bolts accessed from the right side of the receiver, tightened with nothing more than a standard T-30 Torx bit. No gunsmith, no special tools, no fussing. The barrel seats positively every time, and swapping between LMT monolithic barrel assemblies is straightforward. The integrated low-profile gas block and straight gas tube keep your sight picture unobstructed and your action running clean. M-LOK slots run across all eight sides of the handguard, giving you unlimited rail real estate for optics, lights, grips, or accessories without the weight and bulk of traditional quad rails.

The 12.5" handguard length pairs well with short-barrel builds where maneuverability matters—tactical setups, precision intermediate-range work, or compact hunting rigs. The receiver is compatible with LMT monolithic barrel assemblies in .260 Rem, 6.5 Creedmoor, 7.62×51 NATO, .243 Winchester, 7mm-08 Remington, and .338 Federal, so your platform can adapt to different roles and cartridges without buying a whole new upper. Note: barrel sold separately.

This is the heavy variant of the MRP platform—engineered for shooters who prioritize absolute stiffness and aren't concerned with saving ounces. It's a purpose-built tool for precision rifle work.

Key Features

• Monolithic one-piece aerospace-grade aluminum construction for maximum rigidity and repeatability
• Proprietary two-lug barrel-retention system—tool-free removal with T-30 Torx bit only
• Integrated low-profile gas block and straight gas tube for clean sight picture
• M-LOK attachment points on all eight sides of the handguard for modular accessory mounting
• Compatible with LMT monolithic barrel assemblies in multiple large-caliber cartridges
• MRP-H (Heavy) platform variant for maximum stiffness and durability

Specifications

Frequently Asked Questions

What barrels does the MRP-H upper accept?

The MRP-H is designed for LMT monolithic barrel assemblies. It supports .260 Remington, 6.5 Creedmoor, 7.62×51 NATO, .243 Winchester, 7mm-08 Remington, and .338 Federal. Barrels are sold separately.

Do I need special tools to change or install barrels?

No. The two locking bolts are accessed from the right side of the receiver and require only a standard T-30 Torx bit to tighten or loosen. No gunsmith work needed.

Is the barrel included?

No. The upper receiver is shipped assembled but without a barrel. You'll need to purchase a compatible LMT monolithic barrel assembly separately.

What is the difference between the MRP-H and other MRP variants?

The MRP-H is the Heavy variant of the monolithic rail platform, engineered for maximum stiffness and durability. It's the choice when rigidity and precision are the priority.