The Mossberg 940 Pro Field is a gas-operated semi-automatic shotgun in 12 GA with a 3-inch chamber. The 28-inch vent-rib barrel, walnut stock, fiber optic front sight, and tang safety come together in a 7.75-lb package that holds 4+1 rounds. 
 

Key Specifications 

• Brand: Mossberg 
• Model Name: 940 Pro Field 
• Caliber: 12 GA 
• Chamber Size: 3" 
• Action Type: Semi-Auto 
• Capacity: 4+1 rounds 
• Barrel Length: 28" 
• Overall Length: 47.5" 
• Weight: 7.75 lbs 
• Sights: Fiber Optic Front 
• Grip Type: Standard 
• Trigger Type: Standard 
• Safety Mechanism: Tang safety 
• Finish Color: Brown 
   

Detailed Features 

 
The 28-inch vent-rib barrel is the right tool for swing-through shooting on birds and clay targets. Longer barrels provide a more deliberate swing and a cleaner sight picture on moving targets. The fiber optic front sight picks up well in varying light conditions. The Accu-Set choke system ships with multiple chokes (full, modified, improved cylinder) for different pattern requirements. 
 
The adjustable length of pull accommodates different shooter builds. The tang safety sits where the thumb naturally rests for fast engagement. The walnut stock is a traditional choice that holds up to field use without the maintenance anxiety of some synthetic finishes.

The 940 Pro Field Walnut gets consistent praise for its cycling reliability with a range of field loads, the walnut stock's aesthetics and feel, and the overall balance of the 28-inch configuration. Hunters running upland and waterfowl loads report smooth operation without the sensitivity to light loads that some semi-auto shotguns exhibit.

Weight at 7.75 lbs runs heavier than some competing semi-auto field guns, which matters over long days afield. Price sits above entry-level semi-autos, though most buyers find the 940 Pro's gas system and build quality worth the difference. Some owners note a break-in period before the action runs at its smoothest. Aftermarket stock and accessory options are more limited than pump-action platforms.