The Henry Big Boy Side Gate is a lever-action rifle chambered in .357 Mag / .38 Special, built on an American walnut stock with a case-hardened octagonal barrel. The side gate loading port works alongside the traditional tube loading, making reloads faster without changing the rifle's classic character. Capacity is 10+1 rounds, and the transfer bar safety prevents accidental discharge if the hammer is dropped without a trigger pull. 
 

Key Specifications 

• Brand: Henry Repeating Arms 
• Model: Big Boy Side Gate 
• Caliber: .357 Mag / .38 Special 
• Action Type: Lever Action 
• Barrel Length: 20 inches 
• Overall Length: 37.5 inches 
• Weight: 7.84 lbs 
• Capacity: 10+1 rounds 
• Safety Mechanism: Transfer Bar Safety 
• Stock Material: American Walnut 
• Sights: 
  • Rear Sight: Fully Adjustable Semi-Buckhorn with Diamond Insert 
  • Front Sight: Brass Bead 
     

Detailed Features 

The octagonal barrel gives the rifle a 19th-century profile while also providing a flat surface that helps with barrel cooling. The lever cycles smoothly and the fully adjustable semi-buckhorn rear sight can be dialed for both elevation and windage. Because the receiver is drilled and tapped, mounting a scope is straightforward. 
 
The transfer bar safety means the firing pin is only struck when the trigger is pulled, so it can be safely carried with a round chambered. The .357 Magnum chambering is comfortable to shoot and effective on deer-sized game at moderate distances; .38 Special can be used for lighter recoil practice or small game.

Owners of the Henry Big Boy .357 Mag lever-action generally like what they get. Build quality comes up often -- the action is smooth out of the box, the fit between metal and wood is tight, and the case-hardened finish has a distinctive look that each rifle wears a bit differently.

The dual-caliber capability (.357 Mag and .38 Special) is a practical plus. Shooters appreciate being able to use the cheaper .38 Special for range days and switch to full-power .357 when hunting or for defense use. Accuracy reports are consistently good at handgun ranges, and most owners find the recoil manageable.

Weight at 7.84 lbs. gets mentioned -- it's heavier than some alternatives, and that can matter on long carries. Pricing is on the higher side for lever guns, though the general opinion is that the quality justifies it. The historical connection to American lever-action tradition is genuinely part of the appeal for many buyers, not just a marketing angle.