Kel-Tec RDB: A Unique Bullpup Rifle Design

by
posted on December 9, 2020
** When you buy products through the links on our site, we may earn a commission that supports NRA's mission to protect, preserve and defend the Second Amendment. **
kel-tec-rdb.jpg

To say the Kel-Tec’s RDB is an unusual take on a bullpup is understatement. The firearm’s initials—which stand for Rifle, Downward-Ejecting Bullpup—tell only part of the story. It was a big hit at the NRA Annual Meetings & Exhibits in 2014, where it was first unveiled to enthusiasts.

Bullpup designs traditionally eject up top or compromise ambidextrous use by tossing empty cases to one side or the other. In this rifle they leave from behind the magazine well and head toward the ground. The piston-driven RDB is semi-automatic and uses a short-stroke, gas-operattion system.

Versatility is key in the gun, and includes a regulator on the barrel that allows owners to adjust the amount of pressure tapped off for cycling (for suppressor work or when using light loads). It’s also modular, consisting of four assembly groups—bolt group, barrel group, grip group and where the serialized component resides, the receiver group. H&K-style push pins make disassembly for maintenance, repair or replacement fast and easy. Dual ejectors on the bolt ensure operation from unconventional shooting positions, even upside down.

All four versions available today are chambered in 5.56 NATO, feature 1:7" rifling, have a rail on top for optics and accept standard AR-15 magazines. That’s a huge advantage for enthusiasts who already own a modern sporting rifle.

Last year the Kel-Tec RDB was the seventh-most-poplar semi-auto rifle in sales on GunBroker.com. It’s gaining steam, too, because it was No. 8 in 2018.

You can expect it to move up in the rankings when this year’s totals are in, thanks to the company’s introduction of the new Defender RDB model. Its barrel is 16.1" in length, the buttstock is adjustable and it comes with an M-LOK-compatible aluminum handguard. MSRP is $1,072 to $1,142, depending on options.

The RDB Defender version has the same length barrel, but ships with folding sights and no pistol grip. Price varies from $1,036 to $1,108.

If you’re after hogs or hoping to fill a tag on opening day the Hunter model may be more to your liking. With a sleek fore-end, 20.5" barrel and swivel stud up front, expect it to set you back $930 to $1,002.

And finally, the RDB 17 wears a 17.3" barrel. It has a Zytel fore-end, Pitatinny on the bottom for accessories and MSRP is $930.

Latest

.308 Win.
.308 Win.

Handloads: A Quiet .308 Win. For Large-Format Pistols

Of the many commercial .308 Winchester loads, few, if any, are designed for barrels shorter than 16". The one that follows helps address this gap while remaining simple to suppress and light on the wrists.

Court Approves Watchtower Firearms DIP Financing

Watchtower Firearms was granted final approval for debtor-in-possession (DIP) financing by the U.S. Bankruptcy Court for the Northern District of Texas in late June.

Review: Ruger LC Carbine In 10 mm Auto

Following the success of its .45 ACP-chambered LC Carbine, Ruger realized that this platform would go a long way toward making the 10 mm Auto more controllable and fun to shoot, and a new 10 mm version was released in 2024.

The Armed Citizen® July 14, 2025

Read today's "The Armed Citizen" entry for real stories of law-abiding citizens, past and present, who used their firearms to save lives.

Favorite Firearms: A Little Stevens From Chicago

"Over the next five or six years, and before I went off to college, I fired hundreds and hundreds of rounds of .22 BB Caps, CB Caps, Shorts and Longs through this rifle."

Preview: Strike Industries T-Bone Charging Handle

The T-Bone from Strike Industries is an ideal fit for suppressed applications, as it can be configured by the user to redirect gas blowback entirely to either side ...

Interests



Get the best of American Rifleman delivered to your inbox.