Mossberg 500 Duck Gun in 12 gauge with 30-inch vent-rib barrel. Early-era waterfowl specialized variant. Long barrel for distant overhead shots. Type: Shotgun Action: Pump Caliber: 12 Gauge Capacity: 5 Year introduced: 1975, USA Weight: 7.75 oz Overall length: 50" Status: Active Intended use: Waterfowl Hunting