About This Henry Big Boy ModMount
This mount comes with the receiver-specific base and optic-side mount needed to install your optic on a threaded Henry Big Boy receiver. The current components and hardware are listed above.
How the Two-Part System Works
The base fits the firearm receiver and provides the recessed oval ModMount interface. The optic-side mount carries the optic footprint and has a matching oval stud. Two flat-head M4 screws secure the base and optic-side mount together.
Every ModMount optic-side mount works with every ModMount base. This makes it possible to move an optic-side mount between compatible firearm or rail bases. Learn more in the ModMount system guide.
Optional vertical and 45-degree offset spacers install between the base and optic-side mount to raise or reposition the optic. Spacers are sold separately unless they appear in the included-components list.
Compatibility
This receiver base fits Henry Big Boy rifles with threaded receivers.
Installation Notes
Unload and clear the firearm before installation. Remove any factory rail or other mount, position the receiver base on the threaded receiver, and secure it with the supplied two #8-40 x 3/16 flat-head screws.
Seat the optic-side mount, or an optional spacer and optic-side mount, fully in the oval interface. Without a spacer, secure the assembly with two flat-head M4 screws tightened to 10 in-lb dry or 7.5 in-lb with liquid thread locker. Spacers include the longer screws required for their height.
Attach the optic and dry-fit the complete assembly before final installation. Confirm that no optic screw protrudes through the optic-side mount far enough to contact or scratch the receiver.
Tighten the #8-40 receiver screws to 15 in-lb when installed dry. Liquid thread locker is optional; if used, reduce the torque to 11.25 in-lb.
Follow the installation instructions for the complete optic-screw check, torque values, and optional thread locker guidance.
Designed and Manufactured in the USA
Armadyne ModMount bases, optic-side mounts, and spacers are designed and manufactured in the USA. Each component is CNC machined from 6061-T6 aluminum in our Lincoln, Nebraska shop, then sandblasted and finished with H-Series Cerakote for wear and corrosion resistance.
Warranty and Returns
Armadyne stands behind the mounts and components we manufacture. Review our warranty and returns information for support, exchanges, and discretionary return terms.
