I am not a bullpup guy. Two reasons for that: First off, I’ve spent a pretty reasonable amount of time shooting guns where reloading involved inserting a magazine into a hole in front of the trigger, and secondly, I’m left handed. And in case you blessedly unaware righties haven’t noticed, most bullpups involve a bolt whizzing back and forth past the meat of your cheek. If there happens to be an ejection port there… well, it’s not a ton of fun. I’m looking at you, Norinco Type 97.
But there have been some exceptions to the rule. Obviously the Tavor springs to mind, with its ability to switch from right- to left-handed operation with the correct parts, but a left-handed Tavor will set you back somewhere north of $2,500… if you can lay hands on the relatively rare left-handed bolts. And then of course there’s the Kel-Tec RFB. Like the now defunct FN FS2000, the RFB throws its spent cases forward out of a small chute, meaning the receiver is enclosed on both sides. But the RFB shoots .308 Winchester at a dollar per bang, and the FS2000 is perhaps the ugliest gun ever conceived by mankind. And again, the RFB is no cheaper than a Tavor, and the FS2000 is still, for some ungodly reason that should defy anyone with a working pair of eyes, even more expensive.
But now there’s this: The Kel-Tec RDB. A non-restricted, fully ambidextrous, downward-ejecting bullpup chambered in 5.56 that’s set to hit the market for around $1,500.
What it is
In Kel-Tec’s own (seemingly Canadian Forces inspired) nomenclature, the RDB is a “Rifle, Downward-Ejecting, Bullpup.” Sort of like how CF socks are “Socks, Wool, Grey, Itchy” and underwear is “Underwear, Green, Always Too Hot.” Or something like that.
Anyway, it is literally that simple; it’s a bullpup rifle that dispenses its spent casings through an ejection port behind the magazine well, on the bottom of the gun.
Obviously doing this involves a bolt that travels a bit farther than the average rifle’s, as the bolt needs to traverse the entire distance of the magazine well, and then at least a case-length’s span beyond that in order to eject the spent casing through the ejection port. To do this, the RDB relies on an adjustable short-stroke gas-piston system that utilizes a combined gas piston/bolt carrier/op-rod/op-rod guide that houses a sort-of-AR-15ish rotating bolt, albeit with the rounded lugs that are becoming so en vogue and dual plunger-style ejectors.
Those ejectors are mounted at the 12 o’clock position, directly opposite a very healthy extractor that works to keep the spent casing on the bolt face until it reaches the rear of its travel, where the dual ejectors throw the spent casing down the ejection port. And in case you were wondering, the rifle doesn’t rely on gravity whatsoever; the ejectors are forceful enough to eject rounds upwards with the rifle held upside-down.
Why that’s awesome
This means the RDB is fully ambidextrous, and that’s a claim shared only by those aforementioned forward-ejecting exotics. Now before you Tavor owners/enthusiasts/fanatics out there take to your keyboards to tell us to stop making such spurious comments about the Hebrew Hammer, let me explain: Fitting a Tavor with a left-handed conversion kit does not make it ambidextrous. It makes it left-handed. A right-handed person cannot shoot a left-handed Tavor with any more ease or grace than a left-handed person can shoot a right-handed Tavor.
The RDB is different. Since it ejects downward, the rifle can be shot by both lefties and righties alike. The magazine release is central, so it too doesn’t discriminate, and both the 45-degree safety and simple bolt release are present on both sides of the rifle. The only thing that needs to be adapted is the charging handle, which is simply pulled out of the rifle and inserted on the other side.
And all those things work extremely well. The safety is precisely where your thumb goes, the magazine release operates easily, and the non-reciprocating charging handle is easy to use and sprung to fold flat when not in use. It even features a retention notch, so if you don’t want to operate the bolt hold-open (which can be difficult given the gun’s format and layout) you can just pull the handle rearward and lift up. Given how hard it can be to insert a fully loaded mag on a closed bolt, we found ourselves using that notch a lot when first loading the gun, and then charging it with a satisfying H&K MP5-style slap to the charging handle. Of course during firing strings, the bolt locks open on the empty mag so reloads are done using the bolt release, which falls directly under the thumb when inserting a fresh mag. Very handy.
And magazine release, always a point of contention on bullpup rifles, is like the Tavor’s in that you can either bump it with your trigger hand or grab it as you strip a mag out of the rifle. And yes, like damned near everything that shoots from a STANAG mag, the magazines do drop free. Using a 30/5 round USGI magazine provides quite a nice quasi-monopod effect when shooting from the prone position, too, as the bottom of the magazine is basically directly opposite your cheek weld.
Rounding out the RDB’s exterior features are a myriad of sling attachment points; two MASH hook points on each side, two molded in loops on the front of the handguard, and one molded loop on the back.
As with all bullpups, the small explosion that propels the bullet downrange happens right under your face, so it’s somewhat more important that such a gun be built from quality materials to assuage any concerns that an untoward kaboom moment might turn you into Two Face of Batman fame. In the case of the RDB, that comfort comes from a 1.5 millimetre thick (just shy of 1/16th inches) piece of sheetmetal bent into a u-shape, which forms the upper receiver. Inside this u-shape piece, two reinforcing strips are installed on either side, and serve as guide rails for the abbreviated bolt carrier (while also providing purchase for the screws holding the cheekrest onto the receiver’s exterior). The rear of the receiver is given additional rigidity via a small piece that’s welded along the bottom the receiver to form a box. Inside the box, a small stud is installed to locate the end of the operating rod, and a nylon buffer is fitted.
The lower, tasked with nothing more than holding the magazine, ejection port, and trigger assembly, is more familiar Kel-Tec technology; being made of two clamshell polymer moldings screwed together. Inside, the areas surrounding the magazine well, ejection port, and hammer are all reinforced with a web of stamped steel the same gauge as the upper receiver. This is primarily to support the trigger operation… but more on that later. The lower also houses the two or three take-down pins that must be removed to strip the gun. We say two or three because removing all three will break the gun down to its component parts completely, while removing the front two will allow the upper and lower to hinge apart, allowing the bolt to be extracted. The pin through the handguard only serves to retain the handguard.
Finally, we come to the last components: The bolt and barrel. On the model pictured, which is the commercial US model imported and sent to the RCMP for examination, the barrel is 17.4 inches long. On Canadian non-restricted models, the barrel will be 20 inches long, and will feature a 1 in 7 twist rate (this early production sample is 1:9). For the truly geeky, the barrels are AISI 4140 steel, have six grooves in the rifling that twist to the right, and have a corrosion-preventing salt bath nitride treatment internally.
More interesting is the way the barrels are assembled. They use an AR-15 style barrel extension that’s threaded onto the breech, and then locked in place by a lock nut, allowing headspace to be set in much the same way as it is set on a Savage bolt action rifle. This allows for manufacturing tolerances to be compensated for while still obtaining appropriate headspacing. Conversely, AR-15s are more like Remington 700s, where precisely made barrel extensions are threaded onto precisely machined barrel tenons and tightened up against a shoulder machined onto the barrel profile. Also, due to the inability to thread the full length of an AR-15 barrel tenon right up the shoulder, a rebated area between the threaded portion and the shoulder creates a weak point in all AR-15 barrels where the chamber wall is both thinner and unsupported by the barrel extension. This isn’t so on the Kel-Tec RDB barrel, as it is threaded beyond the extension and lock nut, meaning there is no rebated, thinner portion and the lock nut and barrel extension can completely support almost the entire chamber. In short, this is very strong gun.
Even more interesting still is that throwing a micrometer on what threaded portion of the breech tenon we can (most of its threaded length being inside the barrel extension and locknut) would seem to indicate that it’s 13/16″ in diameter, making it the same diameter as an AR-15 barrel tenon, meaning it is likely the same thread pitch as well. However, due to the locknut method of retention, the threaded portion of the barrel is substantially longer than an AR-15 tenon, at roughly one inch long (an AR-15’s tenon is precisely 0.62″ inches long before reaching the shoulder that the extension is tightened against). This, combined with what appears to be a gas port drilled (near as we can tell without removing the gas block) the same distance from the breech as you’d find on a rifle-length AR-15 barrel, would seem to indicate that the RDB barrel is little more than a rifle-length AR-15 barrel with a fancy profile to support the gas block and sight rail/pin attachment points.
The bolt was clearly made with similar logic. Borrowing from the AR-15’s bolt head obviously saves engineering time, but Kel-Tec has rounded the lugs; a feature many high-end AR-15 manufacturers are adopting to increase reliability. It operates on a cam pin that forces the bolt to rotate inside the carrier as the carrier is pushed fore and aft, and the cam pin is retained by the firing pin. If any of that sounds familiar, it should: It’s basically the exact same principle as the AR-15’s bolt operation. The only substantive differences are that there’s a small spring between the bolt body and firing pin (serving to keep the firing pin to the rear during operation), and that the carrier is just an inch and a half long and suspended from an operating rod. Due to the bolt needing to traverse such a distance to eject a spent round, the shorter the bolt assembly, the shorter the receiver can be. The operating rod, by the way, also forms the gas piston and cycles fore and aft on a captive guide rod that lives inside it. The recoil spring driving the gun’s operation is also captive, inside the operating rod.
With most bullpups, the problem with them is twofold: The manual of arms is weird and the triggers are varying degrees of “remind me again why this is a better platform than a conventional gun.” Generally, it seems like the farther a trigger is from the thing it’s triggering, the worse it feels.
Not so with the RDB. Truth be told, were we to close our eyes, the RDB trigger would be nearly indistinguishable from the well broken-in GI trigger in our Colt Canada rifles. Nearly. The break is uber-crisp, right around 4.5 pounds, and very consistent. There’s no weird flexy-feeling hitchiness in it, nor any grit to be found; you pull back and after enough pressure is exerted, it just breaks. But, there’s more overtravel than an AR-15’s (not that it’s excessive, just different), and the reset is both farther away and a lot less pronounced. There’s none of the AR’s nice tactile reset that you feel in the trigger, and even the faint audible snap the sear makes is noticeably far away, literally. It’s like five inches from your ear and you’ll never hear it with ear protection on. But, with that one caveat, it’s fantastic.
And that’s because Kel-Tec put a lot of thought into it. The trigger’s important bits, the ones that contribute to feel, are packed right into the space above the trigger in a steel cage that completely encloses all the relevant components. When squeezed, the trigger releases the sear, which in turn releases a massive action bar that is pulled forward by dual parallel hammer springs housed above the pistol grip. This action bar splits ahead of the magazine well, runs down either side of the receiver, and intersects the hammer. As these action bars are pulled forward, they pull the massive (and weird) hammer forward, which pivots from somewhere near the bottom of the receiver and traverses damn near two and a half inches before it meets the firing pin at the back of the bolt carrier. It’s very strange, but everything is contained within a steel substructure, and is obviously kept very rigid. It works and it works well.
In terms of operation, we did have some trouble with the RDB that we initially and incorrectly thought was the result of certain magazines not feeding correctly. As it turns out, the issue lie with the gun’s almost infinitely variable gas regulator. As delivered from the RCMP evaluation lab, the gas pressures were turned up as high as possible, leading to an issue with double feeds or rounds simply being driven into the breech face rather than the trigger. It reminded us of the issue we initially had with the Type 97, which was also caused by the regulator being turned up too high, so we simply adjusted the RDB’s gas system until it worked. But, we should note that owners would be well served to find a magazine they like and stick to that one type, as doing so will really let you dial the gas system in. Gen 3 Pmags were the most widely reliably (they worked across the most gas settings), but Lancer mags let us turn the gas down the lowest for the softest recoil.
And boy, was it soft. Even with Pmags or USGI mags and the gas system turned up slightly, the RDB is a pussycat. Is it softer than an AR? Well, that’s really difficult to say. We would lean towards “probably,” if only because it did feel a bit softer and logically, all that extra bolt travel is just giving the gun a better chance to bleed off energy that’d otherwise be introduced to your shoulder. Fitted with some sort of compensator or brake, this thing would be absolutely hilarious in CQB matches; already comes back on target quickly and points like we wish our dog would and that’s with an A2 birdcage on the end.
In terms of accuracy, this one is what we’d call rack grade with most of the bulk ammo we shoot most of the time, but we’d like to see what it could do with some 77-grain pills… especially with the commercial 1:7 twist barrels that consumer models will come with. However, due to the way the barrel is pinned to both the sight rail and chassis, it’s quite the opposite of free floated so that may prove the limiting factor on the RDB’s accuracy. But if it’ll shoot into two inches with generic 55- or 62-grain ammo? Well, that’s what we expect from most service rifles (including those aforementioned far more expensive bullpups, so this doesn’t disappoint.
And that brings us to the big question: The price. After all, a $3,000 rifle that shoots into two inches with bulk M855 ammo isn’t as impressive as, say, one that accomplishes that same feat for $1,400. Which is precisely what the RDB is. With pre-sale prices hovering right around that mark, the RDB is roughly twice as expensive as the cheapest centerfire bullpup rifle on the market (the Norinco Type 97), and roughly half the price of probably its closest competitor, the Tavor X95. And in terms of shooting performance, quality, intelligence of design, and overall “goodness,” the RDB punches well above its price point. It’s definitely far closer to the Tavor end of the spectrum than the Type 97 end of the spectrum, and even if you ignore the bullpup format completely, at $1,400 the RDB represents a pretty damned good deal for a non-restricted, STANAG-fed black rifle of any shape.