The Kel-Tec Sub2000 Gen3 is a semi-automatic pistol-caliber carbine chambered in 5.7x28mm with a 16.15-inch threaded barrel (1/2x28). It uses FN 5.7 magazines, has a black polymer stock, and ships with a 20-round magazine. The Sub2000 folds for compact storage. 
 

Key Specifications 

• Brand: Kel-Tec 
• Model: Sub2000 Gen3 
• Caliber: 5.7x28mm 
• Action: Semi Auto 
• Capacity: 20+1 
• Barrel Length: 16.15 in 
• Color/Finish: Black 
   

Detailed Features 

• 16.15-inch barrel threaded 1/2x28 for muzzle devices 
• Accepts FN 5.7 magazines 
• Folding design for compact storage and transport 
• Black polymer stock and matte finish 
• 20-round magazine included

Owners of the Sub2000 Gen3 in 5.7x28mm point to the magazine compatibility with FN 5.7 pistols as a key reason to choose this caliber pairing. Having one magazine type across two platforms resonates with those who already own the FN Five-seveN or want to build a matched kit.

The folding design continues to be the Sub2000 platform trademark: compact enough to fit in a bag or pack, which makes it popular among people who want a carbine that stores easily. The Gen3 upgrades get positive attention for improving the overall operation compared to earlier versions, though some users note the trigger still feels long compared to dedicated carbines.

Reliability with FN-spec 5.7x28mm ammunition is generally reported as solid. A minority of owners mention the grip texture and controls take getting used to, and the lightweight polymer construction gets divided opinions, with some calling it practical and others preferring a more substantial feel.