The Mossberg 990 Aftershock in 12 gauge with an 18.5-inch barrel (brand part no. 83002) is a gas-operated semi-automatic firearm — listed here despite not being a pump gun, though it shares this category’s compact, close-quarters role. Mossberg builds the Aftershock around a durable gas system with corrosion-resistant internal parts, an AfterShock grip that minimizes felt recoil, and an enlarged, beveled loading port for faster reloads. The design runs an ambidextrous safety and a fiber optic front sight, and feeds from a magazine with a 5+1 capacity in an ultra-compact 30.875-inch overall length. Among pump-action shotguns, the 990 Aftershock favors shooters who want semi-auto convenience in the smallest possible package.

Key Specifications

• Chambered in 12 gauge.
• Operates as a gas-operated semi-automatic firearm.
• Features an 18.5-inch barrel.
• Feeds from a magazine with a 5+1-round capacity.
• Overall length is an ultra-compact 30.875 inches.
• Equipped with a fiber optic front sight.
• Fitted with a cylinder bore choke.
• Runs an ambidextrous safety.
• Finished in matte blued steel.
• Ships at approximately 8.04 pounds.

Frequently Asked Questions

Is this a pump-action or semi-automatic firearm? Semi-automatic, gas-operated — listed in this category despite not being a pump gun.

How compact is this firearm? Just 30.875 inches overall, one of the shortest semi-auto designs in its class.

Buy the Mossberg 990 Aftershock Shotgun

Semi-auto convenience in the smallest possible package is exactly what the 990 Aftershock delivers. Order it from our Lubbock, Texas gun shop for fast, insured shipping to your FFL.