The American Tactical Imports S-Beam Pump MB3 is a pump-action shotgun chambered in 12 gauge with a steel receiver and synthetic stock. At 8 lbs and 39.25 inches overall, it's a straightforward working gun with no frills. 
 

Key Specifications 

• Caliber: 12 GA 
• Barrel Length: 18.5 inches 
• Capacity: 4+1 rounds 
• Weight: 8 lbs 
• Overall Length: 39.25 inches 
• Condition: New in Box 
• Manufacturer: American Tactical Imports 
• Model Number: ATIGMB3R 
   

Features 

• Pump action for reliable round cycling 
• Fixed stock for recoil management 
• Blade front sight 
• Steel receiver with synthetic stock 
   
  The MB3 works for home defense, small-game hunting, or range days. The 18.5-inch barrel keeps it maneuverable, and the 4+1 capacity is standard for a gun in this class.

Owners of the ATI S-Beam Pump MB3 generally find it a decent value for the price. The pump action cycles reliably, and left-handed and right-handed shooters alike find it manageable. It handles a range of 12-gauge loads without issue, which is appreciated for a budget-priced gun.

Common complaints center on build quality relative to higher-end shotguns -- the fit and finish aren't going to impress anyone used to Mossberg 500-tier options. The sights are basic and work fine at close range but aren't suited for precise shots at distance.

For buyers who need a functional 12-gauge at an accessible price point, the MB3 delivers. Those wanting tighter tolerances or better aesthetics should look at stepping up the budget.

Mine ran roughly five hundred rounds without a hiccup, though the furniture feels slick.