Mossberg 590 Special Purpose 12 Gauge Pump-Action Shotgun, 20 in Barrel, Heat Shield and Bayonet Lug, 6+1, North Haven USA
Built in North Haven, Connecticut, this Mossberg 590 Special Purpose pairs a 20-inch steel barrel with a factory heat shield and a bayonet-lug/barrel-band at the muzzle. It runs a full-length 6+1 tubular magazine and is chambered for both 2 3/4 and 3-inch 12-gauge shells. The aluminum-alloy receiver is drilled and tapped on top with four plugged holes, and the gun wears durable synthetic furniture.
Condition
Overall Condition: Fair condition, showing extensive signs of prior use and handling.
Bore Condition: Fair - Generally clean, some residue or smudges, slight corrosion.
Specific Condition Notes: There is widespread rust and pitting on the metal surfaces. The chamber face is pitted. Many screws are stripped. There are widespread scratches and blemishes.
What’s Included
- Mossberg 590 Special Purpose 12 Gauge pump-action shotgun
This 590 configuration features a 20-inch barrel with a factory heat shield and a bayonet-lug/barrel-band at the muzzle. It is compatible with M7/M9 bayonets and uses a full-length tubular magazine rated for 6+1 rounds.
It is chambered for 2 3/4 and 3-inch shells and ejects to the right. The ejection port is marked 590 12 GA.
The aluminum-alloy receiver wears a black anodized finish and is drilled and tapped on the top with four plugged holes. A tang-mounted, ambidextrous safety is standard.
The shotgun uses a fixed synthetic buttstock with a rubber buttpad and a 14.5-inch length of pull, paired with a ribbed synthetic forend. Sighting is via a front bead; there is no rear sight.
Additional design notes include the 590 clean-out magazine tube. Receiver rollmarks indicate manufacture in North Haven, Connecticut, USA.

