Mossberg 590 7-Shot Matte Blued 20 Gauge 3in Pump Action Shotgun - 18.5in - The Mighty 590. With decades of military and law enforcement duty and countless performance and success stories under its belt, it's no surprise that the 590 chosen for duty around the globe is also the ideal choice for home defense needs. Dual Extractors Positive Steel-To-Steel Lockup Twin Action Bars And An Anti-Jam Elevator Ensure Smooth Operation Top Mounted Safety Provides For Ambidextrous Operation Overall Length 39.5in