SDS Imports MAC Inertia Tactical Semi-Auto Shotgun 12 Gauge 18.5-inch Walnut

The SDS Imports MAC Inertia Tactical (brand part no. 21000122) is a semi-automatic shotgun chambered in 12 gauge with a 3-inch chamber and an 18.5-inch barrel, running an inertia-driven action rather than a bolt-action or gas-operated system. Military Arms Corp built this shotgun with a 4+1 capacity, ghost ring rear sight, and blade front sight for fast target acquisition, dressed in genuine walnut furniture for a blend of tactical function and classic styling.

Key Specifications

• Chambered in 12 gauge with a 3-inch chamber.
• Fitted with an 18.5-inch barrel for a compact tactical profile.
• Holds 4+1 rounds for extended capacity.
• Runs an inertia-driven semi-automatic action for fast cycling.
• Features a ghost ring rear sight paired with a blade front sight.
• Dressed in genuine walnut stock furniture.
• Weighs approximately 9.4 pounds, measuring 42 inches overall.
• Equipped with RS: Ghost Ring FS: Blade sights.
• Packaged in a compact 3.1-by-8.2-inch retail box footprint.

Frequently Asked Questions

Is this shotgun semi-automatic? Yes, it runs an inertia-driven semi-automatic action, cycling each shot without a bolt-action cycling motion.

What is a ghost ring sight? It’s a large-diameter aperture rear sight paired with a front blade or post for fast, precise target acquisition.

Is this a good tactical or defensive shotgun? Its compact 18.5-inch barrel and fast-cycling inertia action make it well suited to that role.

Buy the SDS Imports MAC Inertia Tactical Shotgun

Get fast inertia-driven cycling in a compact tactical package with the SDS Imports MAC Inertia Tactical (Military Arms). Browse more shotguns and order yours from our Lubbock, Texas gun shop for fast, insured shipping to your FFL.