Mossberg 590A1 12 Gauge Pump-Action, 20 in Cylinder Bore, 8+1, Ghost Ring Sights, Magpul SGA Stock & MOE 590 Forend - Matte Black
This Mossberg 590A1 stands out with its factory 20-inch cylinder bore barrel, full-length 8+1 capacity magazine tube, and robust duty features. It is marked "M590A1" on the receiver and "MODEL 590 – 20 IN. – CYLINDER BORE" on the barrel, with North Haven, Connecticut, USA markings. Outfitted with a receiver-top Picatinny rail, ghost-ring rear sight, protected front post, and Magpul SGA stock and MOE 590 forend, it delivers a proven configuration built for control and durability.
Condition
Overall Condition: Excellent condition, showing only faint signs of any prior use or handling.
Bore Condition: Excellent - Clean, mirror finish, no signs of wear.
Bore Rifling: N/A - Smoothbore cylinder bore (no rifling).
Specific Condition Notes: This shotgun has been very well maintained. The bore is bright and clean.
What’s Included
- Mossberg 590A1 12-gauge pump-action shotgun
- 20 in cylinder bore barrel
- Receiver-top Picatinny rail with ghost-ring rear sight
- Protected front sight post with winged ears
- Full-length magazine tube to the muzzle with bayonet-lug assembly and forward sling loop
- Magpul SGA fixed stock (polymer, spacer-adjustable; 13.0 in LOP as configured)
- Magpul MOE 590 polymer forend with M-LOK slots
The receiver is factory marked "M590A1," and the barrel is rollmarked "MODEL 590 – 20 IN. – CYLINDER BORE," confirming the 20-inch smoothbore configuration. It is chambered for both 2 3/4 and 3 inch 12-gauge shells and uses a full-length magazine tube for an 8+1 capacity.
Sights consist of a ghost-ring rear mounted on the receiver-top Picatinny rail and a protected front post with winged ears. The matte black alloy receiver and overall matte black finish provide a uniform, low-glare appearance.
The shotgun retains core 590A1 features including twin action bars for smooth cycling and a tang safety with a red fire indicator that is ambidextrous in operation. A forward sling loop is integrated with the bayonet-lug assembly at the muzzle.
Furniture is upgraded with a Magpul SGA fixed stock and MOE 590 forend, both in polymer. The SGA stock is spacer-adjustable and set to a 13.0-inch length of pull, while the MOE 590 forend offers M-LOK slots for accessory attachment.
Marked North Haven, Connecticut, USA, this full-size 590A1 configuration delivers the 20-inch cylinder bore setup with ghost-ring sights and robust controls in a straightforward, duty-focused build.