LMT MRP-L M-LOK Hybrid Monolithic Upper Receiver - 9.25"

New for 2026 — the LMT MRP-L M-LOK Hybrid is a patented monolithic upper receiver designed for both piston and direct impingement use, accepting LMT barrel assemblies from 10.5" to 16" with a simple T-30 Torx tool — no armorer's block, no barrel wrench, no timing required.

The LMT MRP-L M-LOK Hybrid 9.25" Monolithic Upper Receiver is a carbine-length one-piece forged aluminum upper receiver and handguard designed for AR-15 piston and DI builds, featuring M-LOK attachment points, Picatinny rail sections at 3, 6, and 9 o'clock, and integrated QD sockets near the ejection port.

The one-piece forged construction eliminates the handguard-to-receiver joint, providing exceptional rigidity for suppressed and precision builds where zero retention across barrel changes matters. Barrel swaps require only a T-30 Torx bit to access two receiver bolts — making barrel changes faster and simpler than any standard barrel nut system. Integrated QD sockets near the ejection port provide sling attachment without additional hardware.

• Platform: MRP-L (Light)
• Construction: Single-piece forged aerospace aluminum (receiver and handguard)
• Handguard Length: 9.25"
• Attachment Interface: M-LOK with Picatinny sections at 3, 6, and 9 o'clock
• QD Sockets: Integrated (near ejection port)
• Barrel Compatibility: 10.5" to 16" LMT monolithic barrel assemblies
• Gas System Compatibility: Piston and Direct Impingement
• Barrel Change Tool: T-30 Torx bit (standard)
• Color: Black
• Barrel: Not included
• New for 2026

Compatibility Note: This receiver is only compatible with LMT patented monolithic barrel assemblies that feature a low-profile gas block with straight gas tube. Standard AR-15 barrels and standard barrel nut systems are not compatible with this receiver. Accepts LMT barrel assemblies from 10.5" to 16". Compatible with mil-spec AR-15 lowers. Barrel is not included and must be purchased separately.

Machined from a single forging of aerospace aluminum for superior rigidity and consistent thermal stability under sustained fire or suppressor use — a meaningful advantage over two-piece upper and handguard systems.

Ideal for piston or DI builds requiring rapid barrel changes, precision or suppressed setups benefiting from monolithic rigidity, and operators who want one upper platform to host multiple LMT barrel assemblies.

Lewis Machine and Tool (LMT) is a U.S. military and law enforcement supplier trusted for precision manufacturing and their patented MRP quick-change barrel system, with decades of field service history behind the platform.