The Glock G40 Gen4 MOS is a 10mm AUTO semi-automatic pistol with a 6.02-inch barrel and 15+1 capacity. At 44.62 oz it's a substantial gun, but that weight helps manage the 10mm's recoil. The MOS cut on the slide accepts optic mounting plates directly without sending the slide out for machining. 
 

Key Specifications 

• SKU: 2024900506 
• UPC: 764503051722 
• Brand: Glock 
• Model Name: G40 Gen4 MOS 
• Caliber: 10MM AUTO 
• Action: DAO (Double Action Only) 
• Capacity: 15+1 rounds 
• Barrel Length: 6.02 inches 
• Weight: 44.62 oz (approximately 2.8 lbs) 
• Sights: Adjustable 
• Grip Type: Black Interchangeable Backstrap 
• Safety Features: Firing Pin / Trigger Block 
• Finish Color: Black 
• Condition: New in Box 
   

Detailed Features 

 
The Gen4 frame uses a rough-texture finish (RTF) and ships with three interchangeable backstraps so you can fit the grip to your hand size. The polymer frame keeps corrosion a non-issue, and the matte black slide finish is standard Glock duty-grade. Adjustable rear sights let you tune elevation for different load velocities, useful with 10mm since pressure/velocity varies widely across factory loads. 
 
The 6.02-inch barrel gives the G40 the longest sight radius in the Glock lineup, which translates directly to tighter groups at distance. This makes it the preferred Glock platform for hunting and long-range pistol competitions. 
 

Usage 

• Hunting: the 10mm cartridge is adequate for deer and hogs at reasonable handgun distances; the long barrel maximizes velocity. 
• Competition: the sight radius and MOS optic capability suit USPSA and similar long-distance handgun events. 
• Home defense: 15+1 capacity with a powerful caliber, though the size makes it less practical for EDC.

The G40 Gen4 MOS has a loyal following among 10mm enthusiasts, and discussions are mostly positive with a few consistent caveats.

Accuracy with the 6-inch barrel gets strong praise. Shooters report noticeably tighter groups compared to shorter Glock 10mm models like the G20. The 10mm caliber's power for hunting and field carry is a recurring theme, with users citing it for deer, hogs, and bear country use. The MOS system is well-received; mounting optics is straightforward and the available plate ecosystem is broad.

Reliability holds to Glock's usual standard. Users report clean function across the wide range of 10mm loadings, from mild to full-power hunting loads.

The main criticisms: the gun is large and heavy at 44.62 oz, which limits everyday carry practicality. Some users find the trigger pull heavier than expected, though this is subjective. A few note the price is higher than competing 10mm platforms. Recoil with full-power 10mm loads is real and worth noting for newer shooters. The weight helps, but it's still a significant step up from 9mm.