Mossberg 500A Mariner 12 Gauge Pump-Action, 18.5-Inch Barrel, Marinecote Finish, 5+1, With Heat Shield, Sling, and Shell Carrier
The Mossberg 500A Mariner is a corrosion-resistant 12 gauge pump-action shotgun finished in Marinecote and built with an aluminum-alloy receiver and steel barrel. This example features an 18.5-inch barrel, 5+1 capacity, and is chambered for 2 3/4" and 3" shells. It comes outfitted with an installed perforated barrel heat shield, a black nylon sling with quick-detach swivels, and a slip-on buttstock shell carrier.
Controls are straightforward with Mossberg's ambidextrous top-tang safety and right-side ejection. The gun retains the 500-series twin action bars and dual extractors. Furniture includes a fixed black synthetic stock with a 14.5-inch length of pull and a ribbed synthetic forend, plus a single front bead sight for simple aiming.
Condition
Overall Condition: Good condition, showing some signs of prior use and handling.
Bore Condition: Good - Clean, well-maintained, minor wear marks.
Specific Condition Notes: This firearm is in solid shape. It has various cosmetic imperfections, scratches, blemishes, and areas of finish loss. The bore remains clean and shiny.
What’s Included
- Sling: Black nylon web sling with quick-detach swivels (installed)
- Shell Holder: Elastic slip-on buttstock shell-carrier sleeve (installed)
- Heat Shield: Perforated metal barrel heat shield (installed)
The Mariner variant applies a nickel-based Marinecote exterior for enhanced corrosion resistance on exposed metal. The aluminum-alloy receiver pairs with a steel barrel and magazine tube to balance durability and weight. Right-side ejection, twin action bars, and dual extractors reflect the model's robust design.
Barrel length is 18.5 inches with a single front bead sight and a 5+1 capacity. The chamber accepts both 2 3/4" and 3" 12 gauge shells. The ribbed synthetic forend and fixed black synthetic stock deliver a stable, weather-resistant setup.
The top-tang safety is ambidextrous and easy to access. Length of pull measures 14.5 inches. Receiver markings read "Mossberg - Made in U.S.A - North Haven, Conn. - 500A - 12 GA." and the barrel is marked "12 GA. - CHAMBERED FOR 2 3/4" AND 3" - U.S.A."
This shotgun comes configured with practical add-ons already installed: a perforated barrel heat shield, a black nylon sling with QD swivels, and an elastic slip-on stock shell carrier. Made in the United States.