Kel-Tec RDB: The Ambidextrous Bullpup Rifle

Kel-Tec RDB with scope mounted Kel-Tec RDB with scope mounted
Kel-Tec RDB with scope mounted (Photo: XY)

The Kel-Tec RDB is a ground-breaking bullpup carbine that has revolutionized the platform. Manufactured by Kel-Tec Industries of Florida, this semi-automatic rifle is chambered in 5.56×45mm NATO. The RDB is a fully ambidextrous bullpup rifle, boasting a patented downward-ejection system, strategically placed magazine catch/release, user-friendly safety, and reversible operating handle. This article explores the Kel-Tec RDB’s distinctive characteristics, including its modular design, adjustable gas piston system, and innovative downward ejection method.

Modular Design

The Kel-Tec RDB was designed in 2015 under the supervision of George Kellgren. The Kel-Tec RDB’s design was intended to be modular, evident in its breakdown into four Assembly Groups held together by HK-style push-pins. These groups comprise the Barrel Assembly Group, the Receiver Assembly Group, the Bolt Assembly Group, and the Grip Assembly Group. The modularity of this design allows for uncomplicated maintenance and customization of the rifle.

The Barrel Assembly Group includes the barrel assembly, optic rail, handguard, gas system, and charging handle. The Receiver Assembly Group primarily contains the serialized steel receiver, butt pad, recoil buffer, and heat shield/cheek rest. The Bolt Assembly Group comprises the bolt carrier, guide rod, recoil spring, and bolt assembly. Finally, the Grip Assembly Group contains the fire controls, trigger and hammer mechanism, magazine well, and ejection port.

Kel-Tec RDB with Trijicon sights mounted on rail
Kel-Tec RDB with Trijicon sights mounted on the rail (Photo: XY)

The modular design of the Kel-Tec RDB offers shooters the convenience of upgrading or replacing individual components per their requirements. For instance, if a shooter wants to switch out their rifle’s handguard, they can remove the Barrel Assembly Group and install a new handguard. This attribute makes the RDB a highly versatile gun that can be tailored to meet the unique needs of its user.

Adjustable Gas Piston System

All Kel-Tec RDB models utilize a highly adaptable gas piston system, allowing users to tailor bolt carrier velocity to mitigate recoil and ensure dependability with various loads, especially when employing a suppressor. The adjustable gas piston system also contributes to the rifle’s cleanliness, as it minimizes fouling and enhances its overall performance and reliability. The gas regulator is integrated into the Barrel Assembly Group to adjust the gas system, empowering operators to modify the amount of gas utilized to cycle the action. This aspect is particularly useful for those who use suppressors, as it reduces gas expelled from the barrel, thereby diminishing noise and recoil generated by the rifle.

Innovative Downward Ejection Method

The RDB’s unique downward ejection method is a key feature that enables shooters to use the rifle from either side, making it a genuinely ambidextrous bullpup rifle. During the extraction and ejection cycle, spent casings are pulled back over the magazine and directed toward the ejection chute directly behind it. As a result, spent brass is sent downwards through the stock, behind the magwell. This innovative design eliminates the need for a side-ejection port, preventing hot gas and brass from flying out and reducing the amount of rifle-generated debris. This feature is particularly beneficial for left-handed shooters, who often struggle to find firearms that cater to their needs.

Kel-Tec RDB rifle
Kel-Tec RDB rifle (Photo: XY)

Furthermore, the RDB bolt features dual ejectors that ensure positive ejection and consistent operation, even when the rifle is turned upside-down. The benefits of this design extend beyond convenience for ambidextrous shooting, as it also improves the rifle’s overall reliability and performance.

Modularity and Easy Maintenance

The RDB’s modular design is a key feature that contributes to the rifle’s ease of use and maintainability. The rifle was engineered to be easily disassembled and reassembled, allowing users to upgrade or customize it according to their needs. The rifle comprises four assembly groups fastened with HK-style push-pins, enabling effortless cleaning and maintenance.

In addition to the benefits of the modular design for ease of cleaning and maintenance, it also facilitates customization. Users can easily swap out barrels, handguards, and other components to adapt the rifle to their preferences. The self-cleaning piston system and chrome-lined barrel enhance the rifle’s durability and corrosion resistance, making it an excellent long-term investment.

The Kel-Tec RDB’s bolt assembly can be conveniently detached for cleaning and maintenance, while the trigger assembly is accessible by removing the grip assembly group. These features make it straightforward to keep the rifle in top condition, ensuring it will perform optimally for years.

Accuracy and Performance

The Kel-Tec RDB’s exceptional accuracy is one of its most notable features. The rifle’s 1:7 twist barrel contributes to its remarkable precision, while the short-stroke piston system ensures reliable operation. The adjustable gas piston system also allows the user to fine-tune the bolt carrier speed, eliminating excessive recoil when firing with a suppressor and ensuring reliable performance with various load types. These features make the RDB an excellent option for sport shooting and tactical applications.

Another impressive feature of the RDB is its trigger, designed to deliver a smooth and seamless shooting experience. Unlike many bullpup triggers known for their poor performance, the RDB’s trigger has been specifically engineered to provide excellent results. With a nice take-up and a clean break, the RDB’s trigger is a joy to use and adds to the overall accuracy of the rifle. Combined with the 1:7 twist barrel, all models of the RDB offer exceptional accuracy that is unmatched by many other rifles on the market.


Kel-Tec has developed the RDB in several different models, each tailored to meet specific needs and applications. The RDB-C is a compact model designed explicitly for close-quarters combat situations. The RDB-S, on the other hand, is a standard model that is ideal for general-purpose use. The RDB-S Survival is an excellent option for those seeking a compact and lightweight rifle for survival situations. The RDB-S Hunter is also designed with a longer barrel, making it perfect for hunting.

The Kel-Tec RDB-S Tactical is an excellent choice for those seeking a tactical application rifle. With a longer barrel and an adjustable stock, this model is designed to provide superior performance in tactical settings. Each model is crafted with specific features to ensure optimal performance for its intended use. The RDB’s versatility and wide range of models make it a top contender for anyone needing a high-quality rifle designed for specific applications.

Ambidextrous Design

The RDB’s ambidextrous design sets it apart from many other rifles. Its unique downward ejection method allows the operator to fire the rifle from either side, making it versatile. This feature is especially beneficial for left-handed shooters who often struggle to find rifles that accommodate their needs. In addition to the downward ejection method, the RDB’s magazine catch/release placement, intuitive safety, and reversible operating handle all contribute to its ambidextrous design.

While other bullpup rifles (FN 2000, Kel-Tec RFB, Desert Tech MDR) have used forward ejection to allow ambidextrous use, these solutions tend to add parts and complexity to the design. Other bullpups can be converted to eject from one side to the other (IWI Tavor, Steyr AUG) but may not be able to do so without special parts.

The Kel-Tec RDB’s ambidextrous design is particularly useful in tactical situations, where the ability to fire from either side can provide a significant advantage. Additionally, the downward ejection method ensures that spent casings are directed downward, preventing them from interfering with the shooter’s line of sight or the line of sight of other shooters. The Kel-Tec RDB’s ambidextrous design makes it an excellent choice for a versatile and reliable rifle.


The Kel-Tec RDB is a unique and innovative rifle that redefines the bullpup platform. Its patented downward ejection method and modular design make it a truly ambidextrous rifle, while its adjustable gas piston system and 1:7 twist barrel provide excellent accuracy and reliability. The Kel-Tec RDB’s ambidextrous design, accuracy, and reliability make it a perfect choice for sport shooting and tactical applications. Whether you’re a left-handed shooter or just looking for a versatile rifle that’s easy to use, the Kel-Tec RDB is an excellent choice.

Pros and cons


  • Simple operation, which makes it easy to use and maintain.
  • The design is clean, which is attractive to collectors.
  • The rifle is compact and lightweight, making it convenient to handle.
  • The rifle has a reliable feeding and ejection system, making it efficient.


  • The Kel Tec RDB is not pro-grade, so it may not be suitable for defensive use.
  • Malfunctions can be challenging to diagnose and fix because of the lack of an ejection port.
  • The trigger and mag release are not as good as other rifles, such as the IWI Tavor X95.
  • Barell Length17.2″
  • Caliber5.56 NATO
  • SightsRail Mounted
  • ActionSemi-Auto
  • Overall Length27.3″

Technical specifications

Country of origin:United States
Manufacturer:Kel-Tec CNC Industries, Inc.
Action:Gas-operated, rotating bolt
Barrel length:17.2″
Caliber:5.56mm NATO
Sights: Rail mounted
Overall length:27.3″
Rate of fire:semi-automatic

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