Kel-Tec RFB Bullpup: A Fresh Approach to Semiautomatic 7.62x51/.308 Platform
By Todd Burgreen
Photos by Nathan Burgreen

Bullpup style rifles have always generated strong opinions both for and against. Pro and con advocates put forth a litany of reasons regarding the concept to support their position. Advocates claim that nothing more than pointless moribund traditionalism is stifling Bullpup-style weapons from being adopted widespread, with detractors denigrating Bullpup effectiveness to the point of challenging the basic raison d’être for the design. Bullpups are firearm configurations in which the action is located behind the trigger group in the space normally solely reserved for the stock. This permits at least a 7-10 inch shorter firearm length for the same barrel length thus improving maneuverability, handling and reducing weight.

While Bullpup examples exist as far back as the early 1900s, Bullpup designs started in earnest after WWII with most sources pointing to the British being at the forefront of development. The ground breaking German StG 44, the father of the assault rifle genre of weapons, prompted this with its high-capacity detachable magazine, select-fire capability, and 7.92x33 Kurz cartridge. The British saw opportunity to get rifle-like ballistic performance out of a package that up to that point had been reserved for SMGs firing pistol caliber cartridges. The emphasis was to find one platform to replace multiple patterns of submachine guns and battle rifles. The WWII experience made it obvious that modern warfare would require the infantry to be armed with a light, compact, selective fire weapon, with effective range of fire much longer than that of a submachine gun, but shorter than that of conventional semiautomatic or bolt action battle rifle. The choice of the Bullpup design was seen as a necessity to retain accuracy while reducing overall length.

Attempts at finding the origin of the term “Bullpup” came up with nothing definitive, with a favorite being that in British usage a "Bulldog" was a heavy caliber revolver firing a .45 caliber bullet from a snub nose barrel. They were based on the Webley Police Revolver for the Royal Irish Constabulary. As most know, British police did not normally carry guns. However, a British policeman in Ireland who did not have a gun was a tempting fate; so they wanted a powerful, yet compact, weapon they could fit under their uniform. It was called "Bulldog" because the archetypical British breed Bulldog has a snub nose, similar to a revolver with a short barrel. Therefore, the British who were early innovators of the modern form of the “Bullpup” rifle associated the earlier term "Bulldog", i.e. a shortened or abbreviated form of a handgun, with the same form for a rifle and thus the endearing term “Bullpup” was born.

The weapon reviewed herein is the Kel-Tec RFB chambered in 7.62x51/.308Win. RFB stands for Rifle, Forward-ejecting Bullpup. The Kel-Tec RFB carbine was introduced at the 2007 SHOT Show. As is sometimes the case with innovative designs, it has taken Kel-Tec longer than they expected to perfect production methods; thus limiting distribution of the RFB to the shooting public. Research for this article indicates the RFB is operated via a short-stroke gas piston with a tilting-block action. Typical of Kel-Tec designs, very little of the RFB is conventional. Initially founded in 1991 as a machine shop, Kel-Tec CNC Industries, Inc. started manufacturing firearms in 1995. Kel-Tec prides itself on specializing in innovative designs for law enforcement personnel and security conscience citizens.

Suarez International instructor and resident Bullpup guru John Chambers was consulted to get his input regarding Bullpup rifles as a whole. When asked to describe Bullpup drawbacks John pointed out that the manual of arms are different compared to “standard” rifles that most of us have more experience with. Another point raised is that some designs are not as ambidextrous as others. The triggers found on Bullpups warranted a response by John as well when asked about drawbacks. John encourages first time users to treat Bullpup triggers like a Glock or Double-Action revolver trigger. One should not try to stage the trigger, but rather work it smoothly, thus allowing a more precise shot. (Neither of these issues are a problem with the Kel-Tec RFB.)

John went on to expound on the positive attributes of Bullpup rifles. His simple response was…. COMPACTNESS!!! An example of this would be working out of vehicles using a conventionally stocked rifle and then run the same drills with a Bullpup. As a driver or passenger you can have the Bullpup rifle pointed muzzle down between your legs, with the buttstock resting on the seat cushion. Movement with a Bullpup inside of structures is much easier and very similar to the size advantage a SMG, like the Uzi or MP5 gives you, without the terminal ballistic penalty. Along the same lines of comparison between the handling of a Bullpup to a SMG, John finds it is also very easy to use a Bullpup with one hand since the center of gravity is farther back, so if you have to open a door, or other similar tasks, the Bullpup offers you an advantage. John feels there are things you can do with a Bullpup that are impossible to do with a standard rifle in a CQB setting; because the Bullpup is so easy to use with one hand, you can effectively treat it like a big pistol if situation demands.

Further making his point about Bullpups, John gives the following example, “I can take a standard size book bag/day pack and can carry the Bullpup rifle, 4+ magazines, binos, rangefinder, communications gear and nobody is the wiser. Consider this scenario; a police officer or soldier in an urban setting needs to move stealthily to a hide site or OP in order to gather intel. With the day pack on his shoulder, he can move into a position to observe, and provide accurate fire from his position of over watch.” John wrapped up our question/answer session with, “There are a lot of shooters that ignore the Bullpup design for a couple of reasons. One is that they can't get past the looks and ‘strangeness.’ They need to get past that because there are a lot of advantages to the design.”

The Kel-Tec RFB’s bullpup profile indicates Kel-Tec envisioned a strictly martial role for the RFB with little consideration for sporting applications. The Kel-Tec RFB weighs less than 9 pounds unloaded and measures 26 inches long including an 18 inch barrel. The barrel is made from 4140 ordnance steel and has a chrome-lined bore and chamber. The barrel of the RFB is not fully free floated; it instead serves as the “backbone” of the weapon. The bolt, receiver, and gas system are also made of 4140 steel with the internal surfaces of the gas system also chromed to resist wear and corrosion. The bolt carrier and upper cover are made of stamped 4130 sheet steel. The grip and forend are made of a high-tech polymer (Zytel). The forend has an integral hand-stop at the lower front to prevent the support hand from sliding forward and touching a hot barrel. Kel-Tec also gave a nod to often heard concerns of using a Bullpup rifle with its action next to the user’s face. The RFB’s breech is separated from the shooters face by two layers of 1.6 mm steel. In the unlikely event of a case rupture, gas expansion is directed downwards through the magazine well to protect the shooters head and face.

The RFB utilizes metric FN FAL magazines, which are widely available at reasonable prices. One 20-round magazine is shipped with the RFB. The FN FAL magazine slides up straight from the bottom not requiring it to be tilted or “rocked” into place. The RFB locks the action back after the last round is fired from the magazine facilitating efficient magazine changes. There are bolt release levers on either side of the magazine housing and an ambidextrous magazine paddle-type mag release centrally located. The safety is also ambidextrous. The charging handle pulls to the rear and is released to chamber a cartridge from the magazine. The charging handle can be quickly switched to either side of the RFB. The use of a common magazine like the FN FAL allows access to other gear designed to accommodate it. A Mayflower Research and Consulting 7.62 Hybrid Chest Rig was used during testing of the RFB. The chest rig is designed to carry three 7.62mm magazines (POF, SR25, M110, DPMS, FN, SCAR H or similar sized) in an integral pouch with an adjustable shock cord retention system closure. The front of the magazine pouch has three general purpose pouches sized to carry the tools of the trade; mini binoculars, laser range finder, GPS, cell phone, PDA etc. The sides of the chest rig have three rows of PALS webbing to tailor the remainder of the chest rig for the mission. The H-style harness features loops to route antennas, comms wires and hydration bladder tubing and is removable via four 1-inch ITW-Nexus side release buckles and designed to be mounted to the front of the Low-Profile Armor Carrier from Velocity Systems. The body of the chest rig has a built in map pocket with a Velcro closure. All buckles are ITW-Nexus IR and all materials and workmanship are 100% made in the USA.

The theme here is evident in that Kel-Tec was committed to creating a truly ambidextrous Bullpup style rifle. A design feature crucial in making it is the patented dual extractor system employed by Kel-Tec. The dual extractor system maintains control of the case from the moment it leaves the magazine and upon firing, pulls the fired case from the chamber and lifts them into an ejection chute above the barrel on the forward movement of the action. The empty cartridge case is not ejected with the rearward movement of the bolt. The empty cases ride/slide down this chute until removed via gravity or pushed out as more cases are added. At first, it was disconcerting not to see cases ejecting to the side as typically found on automatic style rifles. However, this is not possible if true ambidextrous use is contemplated.

The Kel-Tec RFB gas piston system has an adjustable regulator that Kel-Tec labels as the gas restrictor cap. The device is highly adjustable with numerous settings as it is turned in a circular motion. This allows total control on the amount of gas that is delivered to the piston in terms of ammunition used or other variables. Some may find this overly complicated, especially when compared to other adjustable gas systems that feature two to four settings. Kel-Tec designers also turned their attention to correcting the oft criticized trigger feel found on most bullpups due to linkage needed between forward trigger to hammer/sear located in the rear. The Kel-Tec RFB utilizes a floating linkage bar between the sear and the hammer that allows the sear to remain above the trigger. Basically speaking, the Kel-Tec design keeps the sear next to the trigger and the necessary long linkage is located between sear and hammer; thus not impairing the trigger pull.

The RFB has no iron sights, but has a 1913 Picatinny style rail atop the rifle for the mounting of optics. A Trijicon ACOG or Leupold Mk 4 CQ/T would be good examples of sights that many would consider using on the RFB taking advantage of the RFB’s mission flexibility. A Leupold Mk 4 3.5-10 was the primary optic for this review. Winchester 168gr Match, Federal 168gr Match, Hornady 168gr TAP, and Black Hills Ammunition 168gr & 175gr Match along with BHA Gold 180gr AccuBond loads were used with the Kel-Tec RFB. Various kinds of FMJ loads were also used including British and German manufactured 7.62x51mm surplus and Winchester 147gr FMJ. No ammunition, including full metal jacket surplus ammunition, generated greater than 2.5 MOA accuracy levels – with the premium loads producing 1-1.5MOA at 100 yards and 300 yards. After getting past initial range sessions of getting the gas system regulated, the piston driven Kel-Tec RFB proved reliable throughout this evaluation with over 400 assorted rounds sent downrange. The RFB’s 18-inch barrel sacrifices little in terms of 7.62x51mm velocity; with the RFB all the while maintaining a compact package. The handiness gained from the shorter barrel outweighs any velocity lost in this author’s opinion. The RFB’s 18-inch barrel combined with 147gr and168gr bullets produced mid 2,500 fps velocity when fired over a RCBS chronograph.

It did not take an inordinate amount of time to become familiar with the Kel-Tec RFB Bullpup and its handling. The magazine sitting closer to the body took a little getting used to during reloads as well as orientating hand location when racking the charging handle during weapon manipulation. One must pay attention to how optics are mounted on the RFB’s rail. This was learned the hard way involving the Leupold Mk 4 ring bases. The locking nuts need to be located on the opposite side of the charging handle. Along these same lines, the RFB’s charging handle is reciprocating. It usually only takes one incident of coming into contact with the charging handle during firing for a user to correct their grip; thus making it a very quick self-correcting problem.

The Kel-Tec RFB was evaluated by multiple persons – each with extensive prior experience with standard configured AK or ARs. Range tests consisted of moving around barricades and simulated cover while engaging an assortment of paper and steel targets, including automobiles, located at Echo Valley Training Center (EVTC). The compact nature of the RFB was appreciated combined with maintaining full length barrel ballistics for the 7.62x51 chambering. The Kel-Tec RFB showed its true promise by performing not only within the 100 yard bays at EVTC firing from barricades and engaging multiple targets, but also back at the prepared firing position line with targets placed out to 300 yards. Its compact nature makes one forget that it still features an 18-inch barrel. The Kel-Tec attention to detail with the RFB’s trigger design also comes into its own once extended firing distances are encountered.

It seems more of an issue of ingrained conservatism than anything else why more countries/civilians have not taken a liking to Bullpups. The weapon being closer to the body, with resultant center of gravity more toward the rear due to weight of action at the butt, combined with hands being orientated next to each other on the weapon makes the weapon seem lighter than what it is. This contributes to better handling over longer time frames due to lessoning fatigue on the arms and shoulders. Some may question effects of muzzle blast with barrel and action orientated closer than normal to a user’s face during operation. Evaluators did not find this troublesome or noticeable. It was no different than user experience with an SBR and possibly less considering the Kel-Tec RFB offers 18+inches of barrel for powder burn. Firing from the left shoulder during T&E proved very possible with the RFB Bullpup due to its extraction and forward ejection design.

Arms aficionados will find the Kel-Tec RFB’s Bullpup differences with the more typical standard pattern rifles intriguing and may desire one based on this uniqueness. Many will find the RFB Bullpup desirable due to its compactness, reliability, and accuracy. This is a combination hard to argue against in terms of utility for any user.


Kel-Tec CNC Industries

PO Box 2360009
Cocoa, FL 32923
(321) 631-0068

Echo Valley Training Center

This article first appeared in Small Arms Review SAW (December 2012)
and was posted online on November 30, 2012


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