Kel-Tec, an American manufacturer, and developer of firearms, is famous for producing futuristic-looking weapons, and its Forward-Ejecting Bullpup Rifle is no exception. They say its game-like aesthetic makes it a good gun to own, as well as its forward ejection and ambidextrous features such as the early FN F2000’s and the Desert Tech MDR, but it has poor ergonomic qualities.
Read on to know what we think about the Kel-Tec RFB, a rifle developed by the King of Bullpups.
The barrel of the RFB is a medium-contour, 4140 chrome-moly, chrome-lined tube which is shaped to have two lugs that provide attachment points, as well as two sets of threads for different designs of silencers.
It also has six-groove, right-hand twist rifling. At the end of the barrel’s chamber is a steel receiver attached through a receiver collar and barrel nut that threads onto the barrel. The barrel is threaded forward of the collar where another nut locks one of two steel bridge mounts onto an integral barrel lug.
This mount, as well as the gas block mount, form the attachment points for the fore-end along with the two arches where the Picatinny rail is mounted. The integral gas block is also where the chute’s exit hole and tube support is located.
In front of the gas block is a ⅛” diameter threaded section which apparently serves as a suppressor that would slip all the way over the muzzle and flash hider. Lastly, the muzzle terminates in a 5/8-24 threaded barrel portion that accepts the provided lock nut and flash hider or, if you so choose, most .308 Win.-applicable silencers currently available.
From the components of RFB’s barrel or the backbone of the gun, we can say that much time and tooling costs are spent on it.
What makes RFB stand out among the others is that it has an entirely different mode of operation to lock up its chamber when firing. Its well-known features are the tilting bolt and extractors which are engineered to tilt upwards from the bolt face during the rearward portion of the recoil cycle to feed empty casings into the ejection chute above the barrel. When the casing is pushed inside the chute, the extractors move downwards to lock onto the rim of the new cartridges.
It is worth noting that vertically tilting extractors are hard to design in a rotating locking bolt which is an uncommon feature in modern firearms. Guns in the past commonly had tilting bolts. These include the German Sturngeweht 44, Soviet SKS, and Belgian FN FAL. At the moment, modern guns use rotating bolts because they are a stringer, more consistent lockup, and simple design. Rotating bolts also distribute pressure evenly in the rifle because of the simple lug recess contact.
All these strengths of guns with rotating bolt are what the RFB lacks, hence the weak design. But the defense of many for this is that most RFBs have not been around for so long and are not shot hard enough to prove it.
The significant weakness of Kel-Tec’s RFB is its forward ejection chute. Although NRA’s American Rifleman magazine describes its forward ejection as one of the most impressive feats of firearms since FN’s downward ejecting P90, it did not consider that FN made a forward ejecting bullpup about seven years before in the FN F2000.
FN F2000 even had a better design than the RFB because of the same reliable rotating bold system with the fixed extractor. Casings are simply directed into a chute on the receiver wall during the recoil cycle and then the other parts eject the casings when a certain point is reached. It is also devised to save five cartridges in the chute and then eject them all at once which the RFB cannot do.
The RFB is inconsistent when it comes to ejecting. As brass is pushed out of the aluminum ejection chute, it either drops to the ground through gravity if the rifle is held down or it is pushed into a single file up the tube until full, causing jams that can force the first round fired out by the subsequent ones.
On the other hand, the Desert Tech MDR uses a variation on the FN System that basically deletes the chute. A plate that covers the ejection port will catch the cartridges and push them forward. What makes it better than the F2000 and the RFB despite t not being “forward ejecting”, it is still simpler and it allows for more convenient clearance of jams near the chamber and the operation as a conventionally ejecting bullpup.
The RFB uses FN FAL magazines, a pro because it is universally standard. With that, you can readily find suitable r-, 10-, and 20-round magazines if the provided polymer 20-rounder made by Thermold Magazines USA is not enough. However, FN FAL magazines allow them to be inserted straight in, which causes them to be seated too low. This then causes feeding or issues with the bolt stop. They also need to be kicked free or pulled out when the mag catch is depressed, slowing reloads.
The MDR, meanwhile, uses AR-10/SR-25 pattern magazines, which is made from the outset to be straight insert, allowing faster reload and manipulation.
Another downside is while it is fully ambidextrous, you still have to choose which side the charging handle is on unlike the MDR which has charging handles on both sides of the rifle for easier manipulation and reloads from the weak shoulder. Moreover, RFB charging handles also limit what the feasible grips can use on the rifle as it reciprocates.
Lastly, RFB’s bolt catch is just a tiny lever near the mag well that still needs to be flicked in order to be released. This is unlike MDR’s large button which is easier to use when under pressure.
We appreciate Kel-Rec for being an innovative maker of affordable firearms just like the Forward-Ejecting Bullpup Rifle. Despite the interesting design, it has really poor qualities and ejection mechanism which prevents many from adopting the forward ejection chute.
The development of the RFB took long as it was announced in 2007 and was only shipped out to many in 2009. The company said it took testing and re-testing to function reliably but it still looks like a concept-rifle or a prototype.
The bullpup modernization of the FAL design is a great idea, but the design stays in the past for a reason.