The Glock G23 Gen5 MOS is a compact semi-automatic pistol chambered in .40 S&W with a 4.02-inch barrel. The slide has a Modular Optic System cut for direct optic mounting and the pistol holds 13 rounds. These units are factory rebuilt. 
 

Key Specifications 

• Brand: Glock 
• Model: G23 Gen5 MOS 
• Caliber: .40 S&W 
• Action: Semi Auto 
• Capacity: 13 rounds 
• Barrel Length: 4.02 inches 
• Color/Finish: Black 
   

Detailed Features 

• MOS cut slide for direct optic mounting 
• 13-round capacity 
• 4.02-inch barrel 
• Compact G23 frame on the Gen5 platform 
• Factory rebuilt / refurbished condition

Owners of the G23 Gen5 MOS in rebuilt condition mostly report the pistols arrive shooting reliably and looking close to new. The factory rebuild program is a common way to acquire a Glock MOS pistol at a reduced cost, and most owners are satisfied with the mechanical condition on arrival.

The .40 S&W chambering in the G23 frame draws a steady audience despite the caliber's declining share of the market. Owners who already have .40 S&W ammunition or magazines in their inventory find the G23 platform a natural fit, while newer buyers sometimes question the caliber choice against the 9mm alternative.

The MOS slide is the main upgrade draw on this generation. Owners note that the Gen5 MOS cuts are compatible with a range of popular optic footprints, though some report the adapter plates that ship with the pistol are a point of quality variation compared to the optic mounting hardware itself.