Arisaka Zero Retention Clamp for Sig Sauer MCX Spear LT

Eliminate Handguard-Induced Zero Shift

The Arisaka Zero Retention Clamp (ZRC) solves a critical problem with the Sig Sauer MCX Spear LT platform: handguard flex that causes mounted optics and iron sights to lose zero.

The Problem

The MCX Spear LT handguard is not adequately secured to the upper receiver, allowing it to flex significantly under pressure. This flex causes:

• Zero shift of 5 mils or more when pressure is applied to the handguard while shouldering the rifle
• Non-repeatable zero return — the sight may not return to its original point of aim once pressure is released
• Unreliable performance for both lasers and iron sights mounted on the handguard

The Solution

The patent-pending ZRC uses exterior clamps that thread into a special U-bracket. This U-bracket engages the extended upper receiver underneath the handguard, securing it tightly across two axes and virtually eliminating zero shift.

Key Features

• Preserves free-floated barrel — the U-bracket does not contact the barrel or gas system
• Ergonomic design — clamps are contoured to minimize interference with your grip
• Durable construction — black anodized finish for corrosion resistance
• Compatible with: MCX Virtus (5.56 and 300 Blackout) and Spear LT (5.56, 7.62x39, and 300 Blackout)

If you rely on mounted optics or iron sights for precision shooting, the Arisaka ZRC is an essential upgrade for your MCX platform.