Precision Reflex (PRI)
Before the term "Mk12" entered the military lexicon, before desert warfare necessitated FDE variants, this black Gen II top rail helped transform the AR platform into a precision instrument. Developed to replace the original A.R.M.S. #38 Swan rail, this straight-profile design became the foundation of what would evolve into one of the military's most respected precision rifle systems.
In the late 1990s, when NSW and NSWC Crane sought to maximize the AR platform's accuracy potential, the continuous top rail proved crucial. This Gen II design, with its uninterrupted Picatinny surface, solved a critical challenge: maintaining perfect alignment between rear night vision devices and front-mounted IR lasers while providing a stable platform for precision day optics.
Each aspect of this rail serves a specific function. The .450-inch height increase perfectly positions optics for proper cheek weld with standard-height stocks. The three cross-bolt mounting system, combined with the handguard's dual lug interface, creates exceptional rigidity - a feature that proved its worth during extended operations when maintaining zero was mission-critical.
While later variants would introduce features like PEQ-specific sections or modified cuts for Gen III handguards, this straight-rail configuration represents the purest form of the original SPR concept. It's the variant most commonly encountered on early production Mk12 Mod 0 rifles, making it the definitive choice for authentic clone builds.