US Patent No: 10,240,892 - Other US Patents Apply.
The MARKFIVE upper receiver assembly and short-stroke piston operating system is the result of almost two decades worth of understanding and development of these critical components. Correcting the deficiencies in the legacy operating system and later piston systems, the design, manufacture and processing has resulted in outstanding reliability, soft shooting, minimal muzzle rise, and an unparalleled consistency of performance.
Bringing together a number of patented Leitner-Wise technologies in one performance package, the MARKFIVE complete upper receiver delivers the ultimate precision and fighting set up. The heart of this includes the Long Advance Carrier with corrected cam path; Combat Match Bolt; Precision Cam Pin, and Titanium Firing Pin. A Cold Hammer Forged 41V45 CMV Steel 11.5" Combat Match Barrel, 1 in 7 right-hand six groove twist, with Nitrided finish.
Powering the system is the patented Leitner-Wise non-adjustable short-stroke piston operating system. This utilizes a one-piece, fluted, and fully supported operating rod, with true self-regulation for over-pressure. A quick-detachable gas block, for disassembly if required. All heat, pressure and friction surfaces are nitrided then hard chrome plated for durability and adverse environmental condition capability. The operating system is tuned and timed correctly allowing the use of a carbine buffer and spring which minimizes reciprocating mass for smoother operation.
The MARKFIVE Upper Receiver is machined from 7075 billet aluminum with 15 recoil slots, polymer shell case deflector, and polymer ejection port cover. The 9.85" handguard is machined from aircraft grade, heat-treated, extruded aluminum and designed to provide optimum cooling and airflow for the barrel, light weight, and high strength. A ambidextrous Raptor LT charging handle is utilized and all MARKFIVE uppers are supplied with installed eSIGHTS, MARKFIVE carbine buffer and spring, and a Leitner-Wise Heavy Duty Buffer Retainer.
MARKFIVE OPERATING SYSTEM - Patented Short-Stroke Piston System.
BOLT CARRIER GROUP - Full Combat Match Components.