Arisaka Defense Zero Retention Clamp for MCX Virtus/Spear LT



Product Description

Please note: As of 6/27/2023 all U-brackets and clamp covers are hard coat black anodized for all models.

The Patent Pending Arisaka Zero Retention Clamp (ZRC) greatly reduces zero shift for lasers and iron sights that are mounted on the handguard of the MCX Virtus and Spear LT. This version is designed for the MCX Virtus chambered in 5.56 and 300BLK, and the Spear LT chambered in 5.56, 7.62×39, and 300BLK.

The Rattler is not currently supported.

The MCX Virtus and Spear LT handguards are not adequately secured to the upper receiver. This allows the handguard to flex significantly, causing a laser or front sight zero to change when minor pressure is applied to the handguard. A shift of 5 mils or more is possible by pushing on the handguard with your support hand while the rifle is shouldered. Additionally, the zero does not always return to its original position once pressure is removed from the handguard.

The Arisaka ZRC consists of exterior clamps that thread into a special U-bracket. The U-bracket engages the extended upper receiver underneath the handguard. This secures the handguard tightly to the upper receiver across two axis, greatly reducing or even eliminating zero shift. The U-bracket does not touch the barrel or gas system, preserving the free-floated barrel.

The ZRC clamps are contoured to provide minimal interference with the user’s hands while gripping the handguard.

Arisaka is not responsible for any damage caused by improper installation. The ZRC must be uninstalled before removing the handguard from the rifle.

Installation – MCX Spear LT 5.56, 300BLK, 7.62×39 U Clamp

Installation – MCX Virtus 5.56 and 300BLK U Clamp

Weight: 1 oz.

The ZRC clamps and U-bracket are CNC machined from 6061-T651 aluminum and MIL-A-8625 Type III hard coat black anodized.

Made in the USA.




Technical Information

Color / Pattern
Material 6061 Aluminim
Finish Anodized
Firearm Compatibility ,

Catalog Location

California Prop 65 Warning

WARNING: This product can expose you to chemicals, which are known to the State of California to cause Cancer and Reproductive Harm. For more information visit