The KelTec RDB Bullpup 5.56 semi-auto rifle (KelTec part no. RDB20BLK) solves the classic bullpup ejection problem with a downward-eject rotary bolt system, sending spent cases straight down through a vertical chute instead of to the side. That means the RDB is genuinely ambidextrous without a side-eject port throwing brass across a left-handed shooter’s face, all in a rifle-length-barrel package that is dramatically shorter overall than a traditional-layout AR-15.

Key Specifications

• Chambered in 5.56 NATO, the standard AR-15-pattern cartridge with wide ammunition availability.
• The 20-inch barrel delivers full rifle-length velocity in a bullpup-length overall package.
• Weighs approximately 7 pounds.
• Feeds from a 20-round magazine.
• Uses a downward-ejecting rotary bolt system, KelTec’s solution to the traditional bullpup side-ejection problem.
• Runs a fully adjustable short-stroke gas piston, tunable for different ammunition and muzzle attachments.

Frequently Asked Questions

Is the RDB ambidextrous? Yes, its downward-ejection system avoids the side-eject port that makes most bullpups awkward for left-handed shooters.

Why choose a bullpup over a standard AR-15? The bullpup layout keeps a full rifle-length barrel in a noticeably shorter overall rifle than a traditional-layout AR-15.

Buy the KelTec RDB Bullpup 5.56 Rifle

KelTec engineered the RDB to solve the bullpup’s biggest drawback, and the result is a genuinely ambidextrous, compact 5.56 rifle. Backed by KelTec and part of our semi-auto rifles lineup, it is a standout choice for shooters who want a shorter overall package. Order it from our Lubbock, Texas gun shop for fast, insured shipping to your FFL.