The Kel-Tec RDB is a bullpup semi-automatic rifle chambered in .223 Rem / 5.56 NATO with a 20-inch barrel. Overall length is 30 inches; weight is 7 lbs (112 oz). Capacity is 20 rounds. Finish is tan. The receiver has no fixed sights -- front and rear Picatinny rails allow optic mounting. 
 

Key Specifications 

• Manufacturer: Kel-Tec 
• Model: RDB 
• Caliber: .223 Rem / 5.56 NATO 
• Barrel Length: 20 inches 
• Capacity: 20 rounds 
• Weight: 7 lbs (112 oz) 
• Total Length: 30 inches 
• Finish Color: Tan 
   

Detailed Features 

The bullpup layout puts the action behind the trigger, reducing overall length to 30 inches while maintaining the full 20-inch barrel. That combination of compact length and long barrel is the RDB's main appeal. The downward-facing extractor ejects brass below the action rather than to the side, which is practical for left-handed shooters and reduces brass scatter at the range. 
 
The fully adjustable piston system accommodates different ammunition types and environmental conditions. Front and rear Picatinny rails allow optic mounting without iron sights getting in the way. 
 

Target Audience 

Shooters who want a compact overall package without cutting barrel length, left-handed shooters who benefit from the downward ejection, and home defense owners who need a short rifle for maneuvering in tight spaces. 
 

Usage Scenarios 

Home defense where the 30-inch overall length is easier to handle in hallways and rooms than a standard-configuration carbine. Range training where the compact size is practical. Varmint hunting or target shooting where the 20-inch barrel's velocity advantage over shorter carbines matters.

The Kel-Tec RDB receives its strongest praise for compact design and the downward ejection system. Left-handed shooters are particularly vocal about the ejection design, which solves a real usability problem. The 30-inch overall length with a 20-inch barrel is a genuine specification advantage that owners highlight.

Reliability is generally good but comes up as something worth testing across ammunition types before relying on the rifle. The trigger is the most common technical criticism -- owners describe it as functional but less crisp than a traditional AR trigger, a common characteristic of bullpup platforms.

Aftermarket support is limited relative to AR-pattern rifles, which matters to owners who want extensive customization. The stock sights are absent, so an optic investment is essentially required at purchase.

Overall, the RDB appeals most to buyers who specifically want the bullpup format or the downward-ejection system, and less so to buyers who primarily want a conventional AR-pattern experience.