MCX Zero Retention Clamp 5.56
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. This version is designed for the MCX Virtus chambered in 5.56mm with either the Sig Sauer OEM slim handguard or Midwest Industries standard M-Lok handguard. A different version for use with the Sig Sauer SD handguard or Midwest Industries Suppressor M-Lok handguard is available here.
The MCX Virtus handguard is secured to the receiver by a friction fit slot on each side near the extended receiver top rail and a single steel fitting held in place by the front takedown pin. 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 it's original position once pressure is removed from the handguard.
Sig Sauer has resolved this problem on the new MCX SPEAR by adding a fastener on each side of the handguard that securely anchors it to the upper receiver. The Arisaka ZRC plays a similar role for the MCX Virtus by clamping the handguard together at the friction fit alignment slots on the extended upper receiver. This secures the handguard tightly to the upper receiver, greatly reducing or even eliminating zero shift.
The ZRC clamps are contoured to provide minimal interference with the user's hands while gripping the handguard. On the OEM slim handguard the clamps fit in the rhombus shaped vents, while on the Midwest Industries standard M-Lok handguard they occupy one M-Lok slot in the top row. Each clamp is labeled for the side and orientation, making installation easy.
1. The OEM Slim clamps should be placed in the second rhombus vent, as shown in the photos above.
2. The MI Standard M-Lok clamps should be placed in the second M-Lok slot of the top row, as shown in the last photo above.
3. Torque spec: 15-20 inch lbs. While we recommend using a calibrated torque wrench, approximately 15 inch lbs of torque can be achieved by inserting the long end of the included precision fit Allen L-key into the screw head and holding the short end in your fingers, then tightening firmly. Exceeding 20 inch lbs risks stripping the screw head and/or damaging the handguard. Arisaka is not responsible for any damage caused by improper installation.
4. The ZRC must be uninstalled before removing the handguard from the rifle.
Weight: 0.37 oz (OEM slim handguard) 0.47 oz (MI standard M-Lok handguard)
The ZRC clamps are CNC machined from 6061-T6 aluminum and MIL-A-8625 Type III hard coat anodized.
Made in the USA.