The Kel-Tec Sub 2000 Gen 3 is a semi-automatic pistol caliber carbine in 5.7x28mm with a 16.1-inch threaded barrel. It comes with a 20-round magazine, M-LOK rail, and an optic-ready cut in a green polymer stock. 
 

Key Specifications 

• Brand: Kel-Tec 
• Model: Sub 2000 Gen 3 
• Caliber: 5.7x28mm 
• Action: Semi Auto 
• Capacity: 20 rounds 
• Barrel Length: 16.1 in 
• Color: Green 
   

Detailed Features 

• 16.1-inch threaded barrel 
• Optic-ready cut 
• M-LOK rail for accessory attachment 
• 20-round magazine capacity 
• Green polymer stock

Owners of the Kel-Tec Sub 2000 Gen 3 in 5.7x28mm typically lead with the folding design and the 5.7x28mm chambering as the combination that sets it apart. The ability to fold the carbine down for storage while running a bottleneck pistol cartridge appeals to preppers, truck gun buyers, and range shooters who want something unusual.

The Gen 3 update earns positive remarks for improved ergonomics over earlier versions. The M-LOK rail and optic-ready cut address the biggest complaints about older Sub 2000 models, where mounting glass was inconvenient when folded. Owners note the threaded barrel as a practical feature for those who run suppressors or want muzzle device options.

The 5.7x28mm chambering is both a draw and a limitation. Ammunition availability and cost come up consistently in owner discussions, with some finding the cartridge cost prohibitive for high-volume practice. The polymer-heavy construction splits opinions on feel and perceived durability, though most owners report no functional issues with the Sub 2000 Gen 3.