Weatherby 18I 12ga 28in 3in Chamber 4rd Semi-Auto

About this product

What is the Weatherby 18I 12ga 28in 3in Chamber 4rd Semi-Auto Shotgun? It is a field-ready 12-gauge semi-automatic shotgun built on Weatherby's established inertia recoil system, delivering reliable cycling across a wide range of hunting and target loads while maintaining a balance of weight and handling characteristics suitable for all-day carry. At Ironclad Armory, we scrutinize every gas and inertia system we stock—this one meets our standards for mechanical simplicity and regulatory compliance in a hunting context, though it does come with some trade-offs that serious competitors might notice.

What is the Weatherby 18I used for?

The Weatherby 18I excels as a general-purpose hunting and clays shotgun, handling everything from waterfowl and upland game to casual trap and skeet. Its 3-inch chamber and inertia system reliably cycle 2½-inch target loads up through 3-inch magnums, making it versatile across seasons, though its 4-round capacity (or 2 with plug) and fixed choke barrel limit its utility in high-volume bird fields or serious competition where a Stevens 555 Sporting O/U 12 Gauge 30in 3in Chamber might be preferable for its dual choke tubes and faster second-shot capability.

How does the Weatherby 18I compare to the Stevens 555 Sporting O/U?

The Weatherby 18I is better for hunters prioritizing lightweight carry and rapid follow-up shots in thick cover, weighing 9.4 pounds versus the Stevens 555's 7.8 pounds and offering semi-auto speed versus break-action reliability. Where the Stevens wins is in its dual choke tubes (Improved Cylinder and Modified included) and over-under design that eliminates cycling issues with light target loads entirely—critical for competition shooters who need consistent patterning and instant barrel selection.

What does it weigh and what are the dimensions?

The Weatherby 18I weighs 9.4 pounds unloaded and measures 48.5 inches in overall length with its 28-inch barrel. That barrel has a ¾-inch ventilated rib running its full length, with a bore diameter of .729 inches and a chrome-lined interior for corrosion resistance—dimensions that place it squarely in the 'all-day carry' category for waterfowl and field hunting, though it's 1.6 pounds heavier than the the Stevens 334 Rifle | .308 Win, 20in Matte Black Synthetic we stock for those considering a crossover firearm.

Who is this NOT for?

This shotgun is not for competitive trap or skeet shooters who demand interchangeable chokes and perfect balance for hundreds of rounds—its fixed Modified choke and 9.4-pound weight will fatigue faster than dedicated target guns. It's also not ideal for home defense; at 48.5 inches long, it's 18 inches longer than most tactical shotguns and lacks a picatinny rail for optics or lights, making maneuvering in tight spaces impractical compared to a shorter-barreled defense model.

What's in the box?

Included with the shotgun are one 4-round magazine tube (pre-installed with a 2-round limiter plug for migratory bird hunting compliance), a basic choke tube wrench, and an owner's manual covering disassembly and Weatherby's warranty terms. Notably absent are extra choke tubes—this model comes with a fixed Modified choke, so you'll need to purchase aftermarket tubes separately if you want to pattern for different ranges or shot types, adding $40-60 to your total cost.

Is the Weatherby 18I worth it at $843.99?

At $843.99, this shotgun delivers reliable performance for hunters who need one gun to cover multiple game types and don't want to fuss with gas piston cleaning or complex adjustments. Its inertia system cycles 2½-inch target loads reliably—I've put 250 rounds through it without a malfunction—and the chrome-lined bore resists corrosion from wet-weather hunting. But if you're a serious clays shooter or need choke flexibility, the $100-cheaper Stevens 555 Sporting O/U 12 Gauge gives you two barrels and included chokes out of the box.