(This is a reader-submitted review as part of our gun review contest. See details here.)

By Brandon Harker

‘Unobtanium’ has been used to describe many Keltec weapons from the PMR-30 to the KSG and now the subject of this review, the RDB. The RDB is Keltec’s latest entry in their lineup of unique, forward-thinking and often tough to find (locally, but more on that later) wonder guns. ‬

The gun reviewed is an early production gun that was used for cold weather testing by a local LEO. The serial number is sub 40 and it was tested in temperatures that share the same attributes.


Living smack dab in the middle of Alaska made that testing requirement very easy to adhere to. Due to the early production nature of this sample, the specs, models, and options are subject to change. ‬

Keltec has designed this gun to fire the ubiquitous 5.56 round using common AR-15 pattern magazines. This puts it squarely in the same ballpark as guns like the Steyr AUG, IWI TAVOR and the FN FS2000. It is what sets the gun apart that raises this shooter’s eyebrow and the answer lies in the name.

Keltec doesn’t get fancy with model designations and this rifle is no different. RDB, in this case, stands for Rifle Downward-Ejecting Bullpup. It is that downward ejection that makes this a truly ambidextrous action, not just a gun with ambidextrous controls. All controls are ambidextrous full time, except the charging handle that can be swapped to the users preference without tools. ‬Speaking of the lack of tools, let’s open it up to see what we’re working with.


This could not be simpler, as four easily removed pins are all that hold the rifle’s modular components together. I disassembled/re-assembled the gun in the first hour of ownership without the use of a manual and there were zero head-scratching moments.

The rifle breaks down easily into seven main components. These are the receiver, pistol grip/mag well, handguard, bolt carrier group, charging handle assembly, gas piston assembly and barrel/rail/gas adjustment assembly.


The bolt carrier group breaks down with the removal of two pins that are easily pushed out. Putting the rifle back together is where you find that simply installing the charging handle assembly with the handle pointing out of your desired side of the gun is all it takes to set the gun up for left- or right-handed shooters. ‬

Now that we are done poking and prodding the specimen, let’s actually see how it handles. I am not going to lie, I am a fan of bullpups (for the most part). The shorter OAL really makes for a great handling gun that lends itself well to suppressed use. The gun balances well and feels quite small the first few times you shoulder it. The weight is on the light side and very manageable, even with an optic and suppressor added to the kit.‬

For this review, the gun has been outfitted with a Burris AR-332 prismatic scope and a SilencerCo Omega suppressor mounted using SilencerCo’s QD 5.56 muzzle brake.


The gun still feels quite nimble with this setup. Charging has a certain HK feel to it that is more than welcome. Who doesn’t love slapping a charging handle home? The bolt release is easy to access, but doesn’t provide a lot of leverage, so a firm push is required to release the bolt.


The safety is easily reachable for me. Admittedly, I have rather large paws and could see safety manipulation being tougher for those with fingers of shorter stature.

The mag release is interesting and intuitive, requiring just a small rearward movement of the strong hand to drop mags. This is very easy to get used to, but could be a problem of accidental activation with thicker winter gloves. Keltec may have a change in the works as the California model of the RDB already wears an AR-style push button release.


My favorite part other than the great charging handle is the trigger. Bullpup triggers often leave a lot to be desired. This trigger is not only good for a bullpup, it is good for any factory “battle” rifle. Color me impressed.

Reloading seemed to be the only thing that took some getting used to. It is just strange feeling to move the mag back so close to the body, but that will come in time. This is true of most if not all box magazine-fed bullpups.‬


While fondling the gun is fun, shooting it is even better. It is fun and boringly easy to shoot well at the same time. Being able to easily adjust the gas system without tools is excellent once on the range. Especially in this case since I wanted to get an overall impression with running the RDB both with and without a suppressor.

Without the suppressor, the gun has very little muzzle rise. Thread on a suppressor and it feels more like shooting that old Daisy BB gun many of us grew up with than a “high powered rifle.” The soft shooting and good trigger make it easy to shoot the gun accurately, whether you are taking slow shots, double taps, or mag dumps.

I seem to be able to run the gun as fast and easy as an AR if you forgive the occasional blown reload. This particular example proved to be boringly reliable in the roughly 600 rounds of mixed Winchester, Federal, Remington, and Wolf Gold it has been fed. That is a plus, as clearing malfunctions would be rather involved due to the lack of easy access to the chamber. ‬

What about that whole downward ejecting business? I have not forgotten.

The single best part about this rifle eluded me until I put rounds down range. The RDB is a reloader’s dream. Gone are the days of sifting through the bushes for brass and wishing you had adjusted your shooting position. The RDB politely deposits brass in fairly neat piles directly below the gun. Chasing brass is history with this gun and the future is bright, post tumbling of course.


I was able to put the rifle on a CTK Precision bench rest for some accuracy testing while sighting the gun in. The ammo used for testing was run-of-the mill Remington 45 grain JHP. A storm was rolling in so I actually didn’t get to sight the gun in on the trip and just shot a 20-round group off the rest at 100 yards. The gun was hitting paper without even boresighting, so I just ran with it in order to get some data.

The shots were fired roughly one second apart in succession. The rest started to walk up on me a little so the vertical stringing was not entirely due to heat soak. With more time, better ammo, and slower shooting, I believe the RDB can tighten that pattern up considerably. I was pleased with what the gun put out for what I put in. ‬


Overall, I really like the RDB. A lot. I would change very little about the overall package if I could. Keltec got a lot of things right while not having any glaring faults.

I think they have a real winner on their hands, which unfortunately means that these will remain in unobtanium status for the near future. If you follow Keltec on Facebook, you may have seen that they recently upped production on the RDB (to two rifles a week…just kidding) so maybe common availability will come sooner than you think. ‬

Pros: Great ergonomics and handling. Out-of-the-box accuracy. Noteworthy trigger. Brass ejection pattern. Gas adjustability. Magazine release. Ease of takedown. Recoil management. Common magazines. ‬


Cons: Magazine release can be accidentally activated if not paying attention and/or you have the gas set high. Would prefer a better finish on the barrel and gas system. Charging handle material/finish could be better. Malfunction clearing and chamber inspection is impeded due to the design of the rifle. As is customary with Keltec and one of my biggest complaints across the board, the rough plastic finishing.


This gun is leagues better than the P3AT/P32 handguns but still has too much flashing from the molds and poorly finished areas where they attempted to clean those up. Finally, availability. ‬


Specifications: Keltec RDB

Caliber: 5.56 NATO‬
‪Barrel: 17.4″  1/9 Twist‬
Overall Length: 27.4 (27.75 with SilencerCo muzzle brake)‬
Unloaded Weight: 7 lbs‬
Trigger Pull: 5.4 lbs (average of 10 pulls)‬
MSRP: $1272.73

Ratings (out of five stars):

Accuracy: * * * *
The gun has perfectly acceptable accuracy with the limited time I had to wring it out and the ammo used. I look forward to trying out some match ammo and spending some quality time trying to pull better groups.‬

Ergonomics: * * * *
‪The gun handles, charges, and shoots great. For me, the magazine release and safety are good, but I can also see people having trouble with them.‬

‪Reliability: * * * *
The gun never choked with or without a suppressor. 600 rounds is not necessarily a big sample size, but it’s reliability through those 600 rounds of varying type inspires confidence.‬

‪Overall: * * * * ‬
‪Overall, I believe the gun rides the four star line quite well. It is a well-rounded rifle that just works and does enough to sit at the grownup table, but doesn’t do enough to cut the turkey. I can definitely live with that.‬

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35 Responses to Gun Review: Kel Tec RDB

    • Same here.
      I had a P3-AT that would sometimes go into battery…if I was lucky.
      And I had an RFB. It was a similar design to this one, but it ejected the brass along a chute that runs down the side of the barrel. The chute was a square tube with a mostly open top, but enough material on the top to keep the brass from popping out. Then at the opening, there was a slight lip. If an unexpected object (such as the spent primer from cheap milsurp 7.62 ammo, or a tiny pebble) got in the chute between the neck of an ejecting case, and the side of the chute, it would get stuck on the lip, and the chute would jam. And this would cause the action to lock up, because it couldn’t complete the ejection phase the cycle. I had this occur three times, within the first (and only) 500 rounds I shot out of the gun.
      I emailed Kel-Tec about it, with a picture of the jam happening, and a detailed description of how to reproduce it, and nothing productive happened.

  1. The reason that most military grade bullpups still use side ejection is exactly what you stated in your last paragraph: malfunction clearance. Stoppages happen, and being able to see and diagnose a problem in the field overrides any and all advantages downward ejection provides. I’ll stick with my tavors.

      • Please explain how making a system more complicated and more restricted could possibly reduce ejection malfunctions. I’ll wait.

        • My comment was not adversarial and I certainly did not intend to impune your choice of the Tavor. These are sincere rather than rhetorical questions: What is more complicated about the RDB? That the bolt travels further and has two ejectors? Do both ejectors need to function to drop the cases? Does the orientation of the ejection path relative to gravity not figure into how restrictive the port is? I don’t know what the MRBF of either ejection system is. Do you? Overall the RDB looks like the simpler gun to me, but I don’t know enough to be confident in that assessment..

        • I wasn’t trying to be adversarial either. It just doesn’t make logical sense that a system where the brass has to travel twice the usual length backwards and then farther through a longer, more enclosed space could have fewer possible malfunctions than one that simply spits the brass out the side right above the magazine. If nothing else you’re giving the brass more time in the system and more obstacles to overcome before ejection. If the mechanism of downward ejection were somehow vastly simpler than side ejection you might be right, but it isn’t. It works in the P90 only because the magazine is on the top of the gun instead of it’s usual spot. The F2000 had similar issues but at least they put a little door in the top to give you direct access to the chamber. No such luck in the RDB. I predict this gun will fail miserably on even the most modest debris torture test.

    • I well understand the need to visually assess the condition of the chamber and bolt position for condition, to this end I used my RDB as a base for the experiment for this and future weapons of the type(downward ejecting). I found that with training and practice one can, after the tap rack yields no result(slap sharply on magazine, rotate weapon 90 degrees right or left dependent on hand dominance, work charging handle while observing ejection port) transition if circumstances require, when appropriate, drop the magazine, rotate weapon 180 degrees(right hand dominant to the right, left to the left) maintain grip with off hand release firing hand from control group and grasp charging handle. From this position the mag well, chamber and bolt are visible. Diagnosis of stoppage is now possible, I’m still working on procedures for dealing with what you may find but this is a start. All this being said I have yet to experience anything but a failure to feed and that was likely a magazine problem, but I plan for the worst hope for the best. Also as you all probably already know you can ascertain bolt position by observing the position of the op rod. More to come. Thanks

  2. Interesting review. Other than I see KSG all over. I too am quite unimpressed with Keltec quality(had a Pf 9 and. Sub 2000) so I can’t see paying over a grand for THIS…

    • Me too. I am likely even waiting for Mk2. Until then I am quite happy sticking with what I have. I do appreciate Mr. Kellgren’s creativity though.

  3. The SU-16 is one of my favourites, but the reassembly procedure on it was poorly thought out. Looks like George has finally done something about it. Now bring out the RDB-C and I’ll give it a good look.

  4. We cannot trust ANY “Battle Rifle” until it has been “Battle Proven” in actual combat like the AR; AK; and Tavor etc series of guns. Until then it is just an expensive range toy. Deplorable DMD

  5. Apologies in advance for a dumb question, but isn’t downward ejection kinda like dribbling ball bearings down right in front of your feet as you fire and move around?

    In the Sandbox it’s not a problem, on a hard surface, however…

    • Oh! I had not thought of that! Yikes! Guess I’ll stick with the Tavor I have rather than look for one of these Unicorns.

    • your brass, his brass, they’re brass, rocks, grenade pins, belt links, blood , guts, fairy dust….all same same. A non issue or same issue.Life isn’t an indoor range.

  6. I fail to see the appeal of this, when it’s priced pretty close to what Tavor goes for. You lose the downwards ejection, which is a questionable benefit; but you get a much better finished rifle that had a lot more time (and actual combat use) to bake by now.

    • The Tavor is horribly overgassed when supressed, while the downward ejection of the RDB keeps the gas away from the face of the shooter. The RDB is more lefty friendly and has a decent trigger out of the box.

      • From what I’ve heard (here among other places), X95 solved the gas-in-your-face problem of the original Tavor, and comes with a decent trigger out of the box.

  7. 600 rounds including the use of a supressor should be a 5 stars reliability. The gun performed perfectly but got a point deducted?

  8. The California model doesn’t have a standard AR-15 mag release, it has a “bullet button” which is requires the use of a pointy object (like a bullet) to press the release button and is required by CA law.

    That said, I’m in love w the RDB. My LGS has one on the wall and I’ve handled it and I want one bad.

  9. This is on my ‘might’ list. If I see one for 600 its mine. I shoot left and every bullpup that I see puts the ejection port in my face. As far as keltec’s go I’m very pleased with the KSG I just got (200 plus rounds, no problems) and my p3at. I’m converting everything I own to bullpups. Full size AR gone,fullI size shotgun gone. Makes no sense to keep full size weapons when the same accuracy/power can be obtained from the far more compact package. I’ll wait a few years for the mall ninjas to get bored an scoop one of these up at a reasonable price.(Gen 2,3,4,5) by then.

    Oops I thought this was the.308 model. Duh. The .308 model is the one I want. I have the ‘pistol’ in 5.56 and it runs like a champ so I can pass on this.

  10. I wouldn’t mind one of these. I already have a Tavor and FS2000. It’s hard to compare the two except they are both OD green. They each have their good and bad points. The FS2000 with optics does feel a bit lighter and handier than the Tavor. I wouldn’t sell either one.

  11. I purchased one back in July. I saw it in a local pawn shop/gunstore and came back to get it a week later. When I arrived they told me it was broken and they had to send it back. I convinced them to let me take it anyway, figuring it couldn’t really be broken….I was wrong. The hammer follows the bolt home when you charge the weapon, without even pulling the trigger! I took it apart and I don’t see how you can access the trigger mechanism without splitting the lower receiver…which appears to be molded together. I’m going to send it back next week, I like the idea and the aesthetics, but this was going to replaces my mk18 as my patrol rifle. I am not so sure now.

  12. I’m waiting for the CA compliant RDB-C in 6.5 Grendel.
    Now THAT would be a varmint truck gun.

    I hope they give it a little heavier barrel though.

    The pencil barrel on the 5.56 RDB looks a lot like the pencil barrel on the SU16 = 3 MOA at best.

  13. Some sem not to know how a 1919 browning works…306/308…rather well and more movement too. In real combat one tries to have a few other guns close by…to grab as time is short….or just club the foe.Racking the action back does not much in a real jam. KNIFE TIME!

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