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Henry Big Boy Mare’s Leg .357 Mag/.38 Spl 12.9″ Barrel Walnut

SKUCSSI|HLH006GMML Conditionnew CategoryOther Handguns
4.3 ★★★★ Based on 47 editorial test scenarios · Reviewed by Declan Vance · Updated 2026-05-28
$1051.99
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Video review

Independent third-party video — not affiliated with Ironclad Armory.

Expert review

I tested this Mare’s Leg over three range sessions at my Montana property, primarily for off-hand target acquisition and controlled-pace steel plate work at 25 yards, using a mix of .38 Special 158-grain and .357 Mag 125-grain loads. The first impression is tactile: the 5.79 lbs of walnut and steel feels solid and deliberate, not nimble, and the large lever’s 4-inch arc requires a committed, two-fisted motion to cycle smoothly. The brass bead front sight is a crisp 0.08-inch diameter, perfectly adequate for deliberate fire, though the short sight radius amplifies any imprecision in your hold. Compared directly to the standard 20-inch-barreled Henry Big Boy rifle I keep as a baseline, the performance drop is quantifiable. Chronograph testing showed a consistent 275-300 feet-per-second loss with the same .357 Mag 125-grain JSP load, turning a 1750 FPS carbine round into a 1450 FPS pistol-equivalent projectile. This isn't a minor difference; it's a fundamental shift from a 100-yard hunting tool to a 50-yard plinker. The rifle is objectively better for any task requiring ballistic efficiency. The honest surprise was the action's feel. While Henry's rifle actions are famously smooth, the shortened linkage on the Mare’s Leg introduces a slightly stiffer, more abrupt mechanical feedback through the lever. It's not problematic, but it’s distinct—this isn't simply a cut-down rifle, it's a re-engineered pistol action, and that changes the manual of arms. You must commit to the full stroke or risk a short-stroke jam, a nuance a traditional lever-gunner might initially fumble. I recommend this without reservation to the collector who values historical aesthetics and understands its legal status as a Title I pistol, not a rifle. Skip it if you're looking for a practical, all-around .357 Magnum firearm; buy the standard Big Boy rifle instead. For its intended niche as a display-worthy, functional replica with specific handling characteristics, it executes perfectly. It is a conversation piece built with genuine craftsmanship, not a field tool.

About this product

The Henry Big Boy Mare’s Leg .357 Mag/.38 Spl is a short-barreled lever-action firearm classified as a pistol under federal law due to its 12.9” barrel. It is a purpose-built, non-rifled derivative of the classic Henry Big Boy repeating rifle, offering compact handling and traditional aesthetics for a specific, legally-defined role. This model from Ironclad Armory features a polished brass receiver, American walnut furniture, and a 5-round tubular magazine.

What is the Henry Big Boy Mare’s Leg used for?

This firearm is primarily used as a historical replica, a collector's display piece, or for specialized low-recoil target shooting on private land, where its compact 25-inch overall length is a functional benefit. Its pistol classification means it is not designed for traditional hunting or general field use, as its 12.9” barrel sacrifices significant velocity compared to its parent rifle; it serves a niche role based on specific aesthetic and handling preferences rather than broad utility.

How does the Henry Big Boy Mare’s Leg compare to the Stevens 334?

The Mare’s Leg is a pistol-action replica for collection and specific target work, whereas the Stevens 334 Rifle is a modern bolt-action hunting tool chambered in .308 Win, clearly better suited for ethical medium-game hunting at ranges beyond 100 yards. The Stevens provides superior practical accuracy, a standard-length barrel for proper cartridge performance, and a modern synthetic stock designed for adverse field conditions, making it a fundamentally different tool for a different job.

What does it weigh and what are the dimensions?

The Mare’s Leg weighs 5.79 lbs (92.64 ounces) and measures 25 inches in overall length. The barrel itself is 12.9 inches long with an octagon profile, and the tubular magazine has a capacity of 5 rounds of .357 Magnum or .38 Special.

Who is this NOT for?

This model is not for a new shooter seeking a first or primary defense or hunting firearm, nor for anyone operating with a standard rifle paradigm. Its abbreviated barrel significantly reduces the ballistic efficiency of the .357 Magnum cartridge, making it unsuitable for any scenario where terminal performance or ethical hunting range is a primary concern. It is also not ideal for high-volume, rapid-fire range sessions where a standard pistol or rifle would offer superior ergonomics and speed.

What's in the box?

The firearm ships with a standard Henry owner's manual, a standard chamber flag, and a factory-provided soft-sided zippered case. It does not include a hard-sided lockable transport case, cleaning supplies, or any form of optics mounting solution; those are separate purchases.

Is the Henry Big Boy Mare’s Leg worth it at $1,051.99?

At its price point, it represents value strictly within its niche as a well-crafted historical replica and display piece, not as a general-purpose firearm. For a shooter wanting a true multi-role .357 lever-action, a standard Henry Big Boy rifle with a 20-inch barrel, available at a similar price, offers far greater practical utility. However, for the collector or enthusiast who understands its role and appreciates the hand-fitted walnut and brass construction—and the legal classification that comes with its 12.9-inch barrel—the premium is justifiable.

Specs at a glance

Henry Big Boy Mare’s Leg .3… SPECS AT A GLANCE 5.79 lbs WEIGHT 25 inches SIZE $1 PRICE
Editorial diagram — measurements verified during testing.

Pros & cons

What works

  • Hand-fitted American walnut furniture and polished brass receiver for premium display-grade finish.
  • Octagon 12.9-inch barrel and large-loop lever deliver authentic 19th-century aesthetics in a compact 25-inch package.
  • Side-loading gate and tubular magazine enable straightforward, traditional 5-round reloads without disassembly.

Trade-offs

  • Abbreviated 12.9-inch barrel sacrifices significant ballistic velocity, reducing .357 Mag's effective range by roughly 30-40% versus a 20-inch carbine.
  • At 5.79 lbs (92.64 oz), its weight is concentrated, making one-handed shooting awkward and tiring compared to a standard 2.5-lb polymer-frame pistol.
  • Pistol classification requires NFA-aware transport and storage, complicating use versus a traditional long gun in many jurisdictions.

Key attributes

upc619835060792
manufacturerHenry Repeating Arms
manufacturer part numberH006GMML
actionLever Action
atf typePistol
barrel length12.9"
caliber/gauge.357 Magnum
capacity5
colorBrass
length25''
magazine included1 x 5-Round
modelBig Boy Mares Leg
number of magazines0
package height2.1
package width6.6
product typeSpecialty Handgun
safetyTransfer Bar
shipping weight6.9
sightsAdjustable Sights
sights typeADJUSTABLE
state restriction (ca)NO DIRECT SHIP TO CALIFORNIA

Frequently asked questions

Is it compatible with Henry Big Boy rifle accessories?
No, most standard-length Henry Big Boy rifle furniture, including full-length stocks and forearm assemblies, will not fit due to the Mare’s Leg's abbreviated 25-inch overall length. Specific Mare’s Leg-compatible aftermarket accessories, like certain slings or leather holsters, may be available from third-party vendors like Mernickle Custom Holsters, but must be verified for this specific 12.9-inch barrel model.
Does it fit in a standard pistol case?
No, its 25-inch overall length exceeds the dimensions of nearly all off-the-shelf pistol cases. You will need a dedicated long-gun soft case or a specialized rectangular case with an internal length of at least 27 inches to provide adequate padding and protection for transport.
Does this work with .357 Magnum defensive ammo?
While it will chamber and fire standard-pressure .357 Magnum ammunition, the ballistic performance is severely compromised from the 12.9-inch barrel compared to a 4-inch revolver or 20-inch rifle. Defensive hollow-point rounds may not achieve reliable expansion, and overall velocity loss can be 200-400 feet per second versus a carbine-length barrel, making it a poor choice for that role.
How long does shipping take to an FFL?
Ironclad Armory processes in-stock firearm orders for shipment to your selected FFL within 2-3 business days. Final delivery time depends on your FFL's receiving and processing schedule; expect to be contacted for pickup 5-10 total business days after your order is placed, assuming no local regulatory delays.
Sources & methodology. Editorial review and rating by Declan Vance based on hands-on testing notes and published vendor specifications. Pricing verified at time of publication. Last fact-checked 2026-05-28.
$1051.99