The Mossberg 500 FLEX Super Bantam is a 20-gauge pump-action shotgun built around Mossberg's FLEX tool-less interchangeable stock system. It holds 5+1 rounds in a 3-inch chamber with a 22-inch barrel. Overall length is 34.5 inches and weight is 6.5 lbs. The stock is black synthetic with a blued receiver. 
 

Key Specifications 

• Brand: Mossberg 
• Model: 500 FLEX Super Bantam All Purpose 
• Gauge: 20 GA 
• Action: Pump Action 
• Capacity: 5+1 Rounds 
• Barrel Length: 22 inches 
• Overall Length (OAL): 34.5 inches 
• Weight: 6.5 lbs. 
• Chamber Size: 3 inches 
• Sights: Dual Bead Sights 
• Finish: Black Synthetic Stock with Blued Receiver 
   

Features 

The core of this gun's appeal is the FLEX system, which allows the stock and forend to be swapped without tools. Starting with a shorter pull length and extending as the shooter grows is the practical advantage for youth shooters or adults who want to share the gun. Accu-set chokes are included for adapting to different target types. The ambidextrous top tang safety can be operated from either side without changing grip. At 6.5 lbs. and 34.5 inches overall, the gun is genuinely compact and comfortable for smaller-framed shooters.

The 500 FLEX Super Bantam in 20 gauge draws consistent feedback around its adjustability and ease of use. The FLEX stock system is the most cited advantage: owners appreciate that the length of pull can be changed quickly without tools, which is practical for youth shooters who need a shorter pull today and a standard pull in two years. Sharing the gun between shooters of different sizes is another benefit users mention.

Reliability of the pump action is rated positively across a broad range of uses, from bird hunting to home defense. The 20-gauge chambering gets credit for manageable recoil, making it accessible for new or recoil-sensitive shooters. At 6.5 lbs. the gun is light enough for extended carry.

The main critique is cosmetics. The black synthetic components are functional but plain, and some buyers note the finish is less refined than comparable guns. Aftermarket accessory availability for the FLEX-specific connections is narrower than for standard Mossberg 500 stocks. Pricing is generally seen as fair given the versatility the FLEX system provides.