The Mossberg SA-20 All-Purpose Field is a semi-automatic 20-gauge shotgun aimed at hunters and sport shooters who want a light, easy-handling gun without spending a lot. At 6 lbs and 48.5 inches overall with a 28-inch barrel, it handles well in the field for upland birds or small game, and the 4+1 capacity gives you five shots before reloading. 
 

Key Specifications 

• Model: SA-20 All-Purpose Field 
• Caliber/Gauge: 20 GA 
• Action: Semi-Automatic 
• Capacity: 4+1 Rounds 
• Barrel Length: 28 inches 
• Weight: 6 lbs 
• Chamber Length: 3 inches 
• Overall Length: 48.5 inches 
• Stock Type: Fixed Synthetic 
• Sight Type: Bead Front 
   

Detailed Features 

The vent rib barrel aids target acquisition and helps dissipate heat during sustained shooting. The semi-auto action cycles without manually working the action between shots, which matters in situations where follow-up shots count. 
 
It ships with a five-choke set, covering a range from cylinder to full, so you can tune the pattern for clays, upland birds, or waterfowl without buying additional chokes. The fixed synthetic stock resists weather better than wood and holds its shape across temperature swings. Length of pull is fixed, so buyers with non-standard fit may want to check that before purchasing. 
 
The 3-inch chamber handles both 2.75-inch and 3-inch shells, giving flexibility on load selection. 
 

Usage Scenarios 

1. Hunting: The 20-gauge, 6-lb build makes it easy to carry through the field for small game or upland birds. The included choke set covers most hunting patterns. 
    
2. Sport Shooting: At clays or informal range sessions, the semi-auto cycling and vent rib barrel work well for maintaining rhythm between shots. 
    
3. Home Defense: Primarily a field gun, but the semi-auto action and 4+1 capacity make it workable for home protection if that's a secondary consideration.

The SA-20 draws mostly positive reactions, with the weight and recoil being the two most common talking points. At 6 lbs, it's noticeably lighter than most semi-auto 20-gauges, and 20-gauge recoil in a gun this weight is genuinely mild -- experienced shooters tend to agree it's comfortable for long sessions, and it's frequently recommended for younger or smaller-framed shooters moving into adult-size firearms.

Reliability is solid with standard-pressure loads. The issue that comes up in multiple discussions is ammunition sensitivity: the SA-20 can be finicky with light or low-quality shells, occasionally failing to cycle. Sticking with mid-grade or higher-quality loads resolves most cycling complaints. This is a real limitation worth knowing going in, particularly if you plan to shoot cheap bulk ammunition.

The five-choke set and vent rib barrel get positive mentions from clay shooters who like having options without extra cost. The fixed synthetic stock is functional and weather-resistant, though a few users note the length of pull doesn't suit everyone.

The price is a frequent selling point. Against other semi-auto shotguns in the same size and weight range, the SA-20 is one of the more affordable options, and most users consider it a solid entry-level buy with the caveat around ammunition selection.