The Winchester SX4 Waterfowl Hunter in Mossy Oak Bottomland is a gas-operated 20 gauge semi-auto with an Active Valve system that cycles different load pressures without adjustment. At 6 lbs 12 oz with a 28-inch barrel, it's one of the lighter 20 gauge semi-autos on the market. The Mossy Oak Bottomland pattern covers the receiver, barrel, and stock. 
 

Key Specifications 

• Brand: Winchester 
• Model Name: SX4 Waterfowl Hunter 
• Action: Semi-Auto 
• Caliber/Gauge: 20 GA 
• Barrel Length: 28 inches 
• Overall Length: 49 inches 
• Weight: 6 lbs 12 oz (7 lbs) 
• Capacity: 4+1 rounds (2-3/4" shells) 
• Chamber Size: 3" 
• Sights: Fiber Optic Front 
   

Detailed Features 

 
The gas system self-regulates, meaning the gun cycles standard target loads and heavier hunting shells without swapping parts or adjusting the gas port. Three Invector Plus choke tubes are included (Full, Modified, and Improved Cylinder) covering the typical range from close flushes to passing shots. 
 
The Inflex Technology recoil pad absorbs some felt recoil by redirecting it slightly downward, which helps keep the muzzle from jumping between shots. The cocking handle and bolt release are enlarged compared to older SX models, useful when wearing gloves in cold weather. The trigger guard opening is also wider for gloved fingers. 
 
The fiber optic front sight is a practical addition for low-light shooting. The fixed composite stock is straightforward with no adjustment.

Users running the SX4 Waterfowl in Mossy Oak Bottomland mostly focus on two things: how light it is and how well it cycles. The lightweight build is the most common compliment, particularly from hunters covering a lot of ground. The semi-auto action handles wet conditions well in most accounts, with users noting reliable cycling even in rain and cold.

The Mossy Oak Bottomland pattern draws positive feedback for how it works in mixed terrain, hardwood bottoms and flooded timber especially. Fit and finish get favorable comments, with most users finding it comfortable to shoulder and shoot.

Some recoil discussion shows up with heavier loads; a handful of users feel the lighter weight means more felt kick than a heavier gun would produce. There are occasional reports of ammunition sensitivity, with specific shell types cycling less smoothly. Overall sentiment is positive, with most feedback pointing to a capable, well-built waterfowl gun.