The OA Defense 2311 Full Size Pro S is a 9mm 2011-style semi-automatic pistol built on a full-size, double-stack frame. It has a stainless steel frame and slide finished in black DLC, a 5 inch barrel, and an optics-ready slide cut for red dot mounting. The pistol ships with two magazines, giving shooters a choice between a 17-round and a 21-round option. 
 

Key Specifications 

• Brand: OA Defense 
• Model: 2311 Full Size Pro S 
• Caliber: 9mm 
• Action: Single Action 
• Capacity: 21+1 
• Barrel Length: 5 in 
• Finish: Black DLC 
• Material: Stainless Steel 
   

Detailed Features 

• Optics-ready slide cut for red dot sights. 
• Contoured slide with an enhanced trigger and an extended magazine release paddle. 
• Ambidextrous controls for use from either hand. 
• Modular grip with an aluminum magwell for faster reloads. 
• Ships with a 17-round and a 21-round magazine, an owner's manual, and a cable lock.

OA Defense's 2311 lineup draws comparisons to established 2011-pattern guns, and owners of the Pro S generally like the double-stack capacity paired with a single-stack grip feel. The DLC finish gets some praise for wearing well, though a handful of owners have needed to send a slide back for fitting issues, a common growing pain with newer 2011 makers.

For range and competition use, the optics-ready cut and extended magazine release are popular with owners transitioning from double-stack polymer guns. The ambidextrous controls help left-handed shooters, and most reviews describe the trigger as crisp out of the box.

Value opinions are mixed. Shooters comparing the 2311 to bigger-name 2011 builders see it as a reasonable price point, while others note that aftermarket parts and holster support for OA Defense specifically are still catching up compared to more established platforms.