KelTec is known for innovation and affordability, and that certainly runs true with the latest bullpup I got in for review from them. Today, we will be speaking specifically about the KelTec RDB bullpup, a 16-inch barrel, 5.56 NATO, semi-auto bullpup.

I’ve had a bit of experience with bullpups, some more than others. But if you’re interested enough in them to be reading this, you may want to read my last piece, “Ode to Bullpups,” where I discussed bullpups in general. However, the RDB is its own special beast.

Table of Contents

Intro: History
Feel & Function

First Impressions 
Range Testing
Accuracy & Suppression

First a Little History

KelTec RDB Bullpup Rifle
Compact and made in America, the RDB is a unique gun. (Photo: Jeff Wood/

KelTec has been around since the early 90s with a reputation for creating original and innovative firearms in the state of Florida. An overview of KelTec firearms gives the impression that affordability, alternative designs, and unique materials are all part of their operation. My personal experience with KelTec has been modest at best until this RDB came to me, so this review will represent a fresh look at the rifle.

Feel and Function of the RDB

KelTec RDB Bullpup Rifle
Given its size, you get some nice advantages with barricades. (Photo: Jeff Wood/

The RDB is a 5.56 NATO chambered bullpup rifle, the action and magazine are located behind the pistol grip. This makes the rifle a much shorter and well-balanced platform when compared to a traditional rifle such as an AR-15. The RDB is fed by standard AR-type magazines, and rounds are loaded by a piston-driven bolt-carrier system. 

The 16-inch, 1-in-7 twist barrel features a 1/2-28 threaded muzzle that came with a birdcage-style muzzle device as well as an adjustable gas block to control the pressure operating the system. The cunning ejection system that sets the RDB apart from its competition is its downward ejection, whereby the spent cases are pulled behind the magazine and ejected out the bottom of the rifle. 

The controls of the rifle are pretty standard, but not like you are used to for sure. There is a reversible charging handle that can be placed on either side of the foregrip after disassembling the rifle. The safety is ambidextrous and located in the right position – in my opinion – which is exactly where your thumb would expect it to be.

The magazine release and bolt catch are both located behind the pistol grip. The mag release is a stamped piece of metal that reaches around both sides of the lower-rear receiver. There is a push-pad at the front of this horseshoe-shaped piece just behind the pistol grip to release the magazine. 

The rifle locks open upon emptying the magazine. The bolt release is located on either side of the lower receiver but uses a captured lever on the right side of the rifle to aid in leverage to easily release the bolt after loading a fresh magazine.

There is a Picatinny rail across the top of the rifle for sight mounting, and there are several points on the rifle for attaching slings with a hook or other attachment. The Defender handguard features M-LOK slots at three, six, and nine o’clock for attaching additional accessories.

First Impressions

KelTec RDB Bullpup Rifle
While not a precision shooter, the gun can serve many purposes. (Photo: Jeff Wood/

I’ve been seeing KelTec firearms for years and had many opportunities to handle them. When the RDB case arrived, I wasn’t particularly surprised by its contents. Upon opening the case, I shouldered the rifle to give it a feel. It was then that I noticed it was lighter than I had anticipated, coming in at 6.7 pounds according to KelTec. This was a pleasant discovery.

I played with the rifle for a few minutes to get a full understanding of its operation and features, and then I stared at it for a bit. At first, I thought it appeared like a high school or college engineering class had drawn this thing on a computer, but the more I looked at it the more I could see what they were getting at. 

The bullpup balances like most others I’ve held, right at the grip area. I again ran the charging handle a few times. The handle can be pulled to the rear and lifted into a locked position to leave the action open. But since the ejection port is at the bottom, there isn’t really a place to inspect it.

I wanted to try out the trigger, which for many bullpups is famously terrible. To my surprise, the trigger was not bad. The first stage gave way to a solid wall that broke cleanly and firmly. So firmly in fact I almost immediately felt the desire to open up the rifle and see what was making such a significant strike when I pulled the trigger. Internal inspection showed a very curious design, with both the hammer and trigger mechanisms being far from what I’d imagined.

Inspecting the Internals

KelTec RDB Bullpup Rifle
KelTec does show off its ingenuity. (Photo: Jeff Wood/

The hammer itself is not unlike a turkey wishbone, with two legs coming together at the top to form a hammer and anvil. The hammer splits around the magazine well, and the sear/connecting linkage travels all the way up to the trigger group. The whole thing is quite interesting and explains why the trigger feels so good compared to other bullpups.

While inside, I noticed the very short bolt carrier. The bottom ejection requires the bolt face to travel far enough behind the magazine to allow spent cases to clear the magazine and trigger parts. The short bolt and firing pin are similar to most other semi-auto bolt designs, with a rotating bolt guided by a cam pin that also locks into the receiver guide rails as it goes into battery.

With a fresh perspective, I reassembled the rifle and went to work preparing it for a range session. The rifle had come with a set of Magpul flip-up sights, but I also added a SIG Sauer Romeo RDS. I was surely going to try the rifle suppressed as well to see how the adjustable gas system could accommodate the difference.

On the Range

Once on the firing line with some 30-round magazines, I loaded the RDB and prepared to fire. Initial ergonomics were not bad, and the rifle fit me well. The charging handle on the left side of the rifle was easy to find blindly and provided plenty of purchase. With an easy click of the safety, I was in business. 

The compact bullpup gives you a gun that over-performs its size. (Photo: Jeff Wood/

Recoil was not bad at all and just what I expected from a 5.56-caliber bullpup. The spent shells began to pile up neatly on the ground in front of me. When my first magazine went empty, it was time to try out the reloading controls of the rifle. Stuffing magazines through the rifle and doing lots of reload drills taught me a couple of things about the RDB.

It could use a more flared magwell, as it seemed a little bit of a stickler to get the magazine stabbed in properly. The magazine release worked better than I had anticipated, almost too good. I have long heard of people complaining that the mag release is too easy to inadvertently drop the magazine while maneuvering the rifle. And it proved to be so for me as well. A slightly miscalculated move of the shooting hand can drop your magazine from the rifle. 

The bolt release took some time to get used to as well, reaching back and hitting it with my right thumb seemed to be the best option. I’m sure with some training it could become second nature. 

Cross-training on different rifle platforms doesn’t hurt anyone, and it’s a bit of a pet peeve of mine when bullpup haters act as though slight retraining in operation somehow renders a gun “useless” in their opinion.

Accuracy and Going Suppressed

KelTec RDB Bullpup Rifle
Some love the look of a bullpup, and some people hate it, but the RDB has a profile that is all its own. (Photo: Jeff Wood/

The RDB wasn’t particularly accurate for me. With a scope installed, I wanted to see how the rifle shot at 100 yards. For this, I used some of my better shooting ammo, which used Hornady 55-grain V-Max bullets. Groups averaged around 2 inches with an assortment of ammunition types, which is not terrible and certainly useful for many purposes.

Shooting several hundred rounds of ammo was quite a bit of fun. The RDB seems to flow nicely from shot to shot. I adjusted the gas valve to a lower setting for shooting with my Yankee Hill Machine R9 suppressor. This made the rifle even more pleasant and soft shooting. I could have gone all day with it like that. 

The only malfunctions I noticed were a couple of times when I did have a failure to lock back on an empty magazine. I’m not sure why as I was never able to force the issue. That’s not a huge deal, but it’s something worth noting.


I came away from this review a little impressed and a little bit satisfied. The RDB appears to be a fine rifle for whatever purpose you might apply it to. I guess I could say I wanted to like it more, but there are a few things I dislike. The good news is that most of my objections are subjective, so they may not matter to you.

It was hard for me to get over the looks of this gun. I’m not sure why KelTec guns all seem to look so much like toys to me, but they do – Like a Nerf gun that has been painted black. The RDB shares that KelTec heritage even if it functions flawlessly. 

The accuracy of the rifle was mediocre for my taste, but it could be used for a great many purposes depending on your accuracy requirements. Other than that, it’s a fun gun to shoot, and for the most part, it works well. It would make a good truck gun, but the price might be hard to swallow for the average gun owner. Again, bullpups aren’t exactly for the average firearms enthusiast. 

The compact design requires innovation and design work, like I mentioned above, and those innovations cost money and take time to figure out. If you want an American-made rifle from a company that drives these kinds of modernizations, then the KelTec RDB is for you.

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