ABOUT THE PARALLAX

ABOUT THE PARALLAX

The Parallax system developed through multiple design phases beginning in 2022.

Initial validation began with a simple PLA riser mounted to an ADM QD T1 base. The purpose was to establish viable optical centerline height and usable objective diameter at the furthest practical position along an AR-15 upper receiver.

Three primary architectures were evaluated:

• Forward, separate Picatinny riser

• Combination clamp mount

• Bridging spacer

The combination clamp mount offered maximum rigidity but increased weight and cost.
The forward tower provided flexibility across prism models but required height concessions.

Evaluation ultimately identified the Primary Arms SLx 3X and 5X MicroPrisms as optimal for the intended role. The preferred 1.54” prism centerline required a 2.7–2.8” optical centerline for a piggyback T1-pattern red dot.

An early MJF nylon tower prototype remained mounted on a carbine for approximately one year of regular handling and transport. The prototype maintained zero throughout this period, validating structural integrity and height selection.

A parallel spacer concept was evaluated within an M14 sight pocket. While the 5X prism is not ideally suited to that platform, it served as a useful test case for systems lacking a mature Picatinny ecosystem.

Subsequent revision refined spacer geometry and introduced a contoured sunshade that resolved both optical and physical integration concerns. That revision became the production configuration.

DESIGN OBJECTIVES

The Parallax system is engineered to:

• Enable cost-effective optical stacks using proven mid-tier optics

• Prevent objective lens glint without reliance on honeycomb ARDs

• Allow rapid lens clearing in adverse weather

• Achieve the lowest practical RDS centerline relative to the prism

• Maintain preferred prism placement on AR-pattern carbines

• Support threaded red dot sunshades (#5-40 front threads)

• Integrate with factory bases and common aftermarket mounts

The intent is system optimization, not component novelty.

COST AND WEIGHT CONTEXT

Optics

Primary Arms SLx 5X MicroPrism — ~$400, ~7 oz
Holosun 403/503/ARO, Vortex Crossfire II — ~$120–220, ~3 oz
Griffin Armament GPS1X — ~$345, 6.3 oz

Parallax System

Spacer, shade, and hardware — ~$200, ~5 oz

Total Stack Weight

~15–18 oz depending on optic selection

COMPARISON TO ACOG SYSTEMS

The 5X configuration aligns most closely with the Trijicon TA55 (5.5×50) and TA02 (4×32 LED).

For reference:

TA55 — 25.6 oz
~$1,700 street / $2,328 MSRP

TA02 — ~17.5–18 oz
~$1,200+ street / $1,750 MSRP

A comparable Parallax 5X configuration totals approximately $800, offering significant cost reduction and weight savings relative to a TA55-based stack.

GPS1X-based configurations achieve similar total weight under $1,000.

The system prioritizes practical performance, modular compatibility, and cost efficiency within a durable, American-produced architecture.