Henry Big Boy Mare's Leg Side Gate .45 Colt Lever Action Pistol - 12.9" Barrel, 5rd Capacity

The Henry Big Boy Mare's Leg is a distinctive lever-action pistol in .45 Colt that bridges the gap between classic cowboy aesthetics and modern shootability. With its 12.9" octagon barrel, large-loop lever, and side-loading gate, this is a rig that demands attention at the range or around camp. Built on Henry's reputation for quality lever guns, the Mare's Leg offers the smooth, intuitive action that makes .45 Colt a favorite among handgun hunters, Cowboy Action shooters, and collectors who appreciate functional firearms with real character.

The pistol feeds from a 5-round magazine and tips the scales at 5.79 lbs—substantial enough to handle recoil but nimble compared to a full-sized carbine. The receiver is polished hardened brass, the barrel is blued steel with a 1:16 twist, and the grip is American walnut with a brass buttplate. A transfer-bar safety keeps the gun secure in the holster, while the fully adjustable semi-buckhorn rear sight (with diamond insert) and brass-bead front sight are set up for practical shooting distances. If you want to mount glass, the receiver is drilled and tapped for Henry's BB-RSM scope mount.

This is a gun for people who don't follow trends. The side-loading gate makes feeding rounds intuitive, the large loop lever won't snag on clothing or gear, and the .45 Colt chambering pairs ballistics that respect recoil with bullet energy that matters at working distances. Whether you're building a Cowboy Action rig, hunting hogs or deer where terrain calls for something lighter than a rifle, or simply want a lever gun that turns heads, the Mare's Leg delivers both form and function.

Key Features

• Lever-action .45 Colt with 12.9" octagon barrel
• 5-round capacity with smooth side-loading gate
• Large-loop lever and saddle ring for classic handling
• Polished brass receiver and blued steel barrel
• American walnut furniture with brass buttplate
• Fully adjustable semi-buckhorn rear sight and brass-bead front
• Transfer-bar safety for secure carry
• Drilled and tapped for scope mounting (Henry BB-RSM compatible)
• Built for Cowboy Action, hunting, and collector appeal

Specifications

Frequently Asked Questions

Is the Henry Mare's Leg suitable for Cowboy Action Shooting?

Yes. The .45 Colt chambering, side-loading gate, and large-loop lever are all hallmarks of Cowboy Action design, and the 5-round capacity fits SASS rules. The mare's leg configuration has been a mainstay in that sport for years.

Can I mount a scope on this pistol?

The receiver is drilled and tapped for the Henry BB-RSM scope mount, so yes—if you want to run glass, Henry's dedicated mounting system is designed to work with this rifle.

What is the side-loading gate and why does it matter?

The side gate lets you load rounds directly into the magazine from the side of the receiver, rather than through the loading gate at the bottom. It's faster, easier, and more intuitive for shooters who want to top up or reload on the move.

What's included with the Henry Big Boy Mare's Leg?

We don't have details on what ships in the box, but the pistol comes equipped with the sights, ring, and buttplate described in the specs. Contact us if you need specifics on any accessories or documentation included.