In the late 1970s James Sullivan, one of ArmaLite’s former chief designers and one of the men responsible for the M16, began developing a new light machine gun for a company in Singapore. The Ultimax 100 is a 5.56x45mm, gas-operated magazine-fed light machine gun. It uses a short stroke gas piston system that acts on a continuously recoiling bolt.
Sullivan was originally approached to develop a new select-fire intermediate cartridge rifle for the Singaporean military. Working with Chartered Industries he developed a very lightweight light machine gun. Sullivan was especially interested in recoil mitigation and developed the Ultimax’s bolt to travel rearward without ever hitting a buffer or the receiver. This greatly lowers perceived recoil and makes the weapon much flatter shooting.
The Ultimax fires from an open bolt (which uses a multi-lug rotating bolt head) and has a non-reciprocating charging handle. It’s buttstock can be removed to make the weapon even more compact. The absence of a buffer in the butt allows the weapon length to be reduced to just 81cm (32 inches), making it an excellent weapon for jungle or urban combat. The Ultimax is also extremely light for a squad automatic weapon, weighing approximately 4.7kg unloaded, and around 6.5kg when loaded with a 100-round drum.
While the MkII Ultimax has a fixed barrel, the MkIII has a quick change barrel which releases by pulling a catch the the rear and simply twisting the barrel and pulling it forward. Unlike other machine guns the bolt can remain forward when the barrel is being removed.
The Ultimax feeds from either an adapted STANAG magazine or a 100 round drum magazine, which has a controlled internal feed rather than a belt. The drum was co-developed by Sullivan and Bob Waterfield. The weapon’s rear pistol grip is similar to the Stoner 63 weapon system’s (which Sullivan had also worked on) while the smaller, grooved front pistol grip is reminiscent of the classic Thompson submachine gun’s.
It is said that Singapore’s government would not allow the Ultimax to be entered in the US’ Squad Automatic Weapon trials as the US government had refused them the technical package for the M16. Other sources suggest there was a commercial disagreement between Colt and Chartered Industries Over region sales of the M16. As a result the FN Minimi won the trials and was adopted as the M249. Those who have fired both claim that the Ultimax would have given the Minimi more than a run for its money. Despite this the Ultimax has seen action around the world and has been in service with the Singapore Army since 1982.
An updated version was offered in the US Marine Corps’ Infantry Automatic Rifle trial but was beaten by Heckler & Koch’s HK416, now the M27. ST Kinetics, formerly Chartered Industries, continues to improve and produce the Ultimax with the Mk8 introduced in 2012.
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Vic brings us the second part of his special episode looking at the story of the AR-10, with a very unique run down of various variants of Eugene Stoner’s weapon. Vic runs us through every production model made by Artillerie Inrichtingen as well as several special prototypes and transitional models.
After a recap look at an example of a Hollywood-made rifle Vic shows us how the AR-10 worked using an instructional cutaway model. Throughout the video Vic examines all of the major production guns, beginning with an early A.I. production gun that incorporates the same ‘beer can’ muzzle device as the original American-made rifles. Vic then takes us through a series of rifles that represent the evolution of the design.
Beginning with the Cuban model, with its pencil profile barrel and top mounted gas tube. This model was also trailed by both the Dutch Army and the German Bundeswehr. Later in the video Vic gives us a quick look at the various German trials rifles the FAL (G1), the SIG 510-1 (G2), the H&K/CETME (G3) and the AR-10 (G4).
Vic follows the Cuban model with a look at the Sudanese Model, with its bayonet lug sleeve, and the Guatemalan variant which swaps out the bayonet lug for rifle grenade launching capability. The Sudanese military ordered 2,508 rifles from A.I.
In addition to these Vic also gives us a look at an extremely rare prototype carbine, a sporter model (the AR-102) and a prototype squad automatic weapon with a heavier profile barrel. Vic then takes us through the features of the final A.I.-made variant, the Portuguese or NATO model. The rifle was officially adopted by the Portuguese army’s Caçadores Páraquedistas (paratroops) and saw action in Angola, Portuguese Guinea and Mozambique.
Vic then takes a look at a series of rare variants and one-offs, including a rifle with green furniture made for Prince Bernhard, the Royal consort to Queen Juliana of the Netherlands, and a heavy barrelled magazine-fed squad automatic rifle with a rubber butt-pad and additional folding carrying handle.
To round out the story of Artillerie Inrichtingen’s involvement with the AR-10, Vic is lucky enough to take a close look at an M1 Garand adapted to feed from surplus AR-10 aluminium waffle magazines. This concept was developed to equip the NATRES, the Dutch Army Reserve, and was based somewhat on the Italian Beretta BM-59. Vic shows us both a very early prototype BM-59 and one of only two A.I. Garand adaptation prototypes.
In this first part of a TAB special episode examining the history of the ArmaLite AR-10 Vic discusses the early origins, history and development of the now legendary 7.62x51mm rifle. At the heart of this episode is a remastered version (certainly the best currently available online) of the c.1958 ArmaLite/Fairchild promotional film that features Eugene Stoner and shows many of the early ‘Hollywood’ Armalites in action! The first part of this special documentary concludes with Vic examining a Hollywood-made AR-10B (the last iteration of the US-made AR-10s).
Much has been written about the AR-10, Eugene Stoner and the genesis of the AR-15’s parent rifle. It’s a design which owes much to many: Stoner, George Sullivan, Melvin Johnson and later the engineers at Artillerie Inrichtingen.
ArmaLite, formed by George Sullivan with the help of Richard Boutelle, President of the Fairchild Engine and Aircraft Corporation, began work on the first AR-10 prototypes in 1955. Designed by Eugene Stoner, using his patented direct gas impingement system. Stoner patented this system in 1956, with the patent being granted in September 1960 (US #2,951,424).
The AR-10 had an aluminium-alloy forged receiver, an in-line stock, polymer furniture and chrome-lined steel parts. While conventional steel barrels were the norm an ill-fated attempt to use an aluminium/steel composite barrel during US Army evaluations proved disastrous when the steel inner parted from the aluminium outer and caused the barrel to burst. As a result of these weight saving efforts the rifle weighed just ~3.4kgs/7.5lbs unloaded. The Armalite AR-10 had a side mounted gas tube, a top mounted charging handle and fed from 20-round box magazines. One of the most interesting features was the large aluminium muzzle device, fitted to some ArmaLite-made Rifles, which reduced sound and flash.
In 1957, ArmaLite sold the AR-10 manufacturing rights to the Dutch small arms manufacturer Artillerie Inrichtingen, while US manufacture was licensed by Colt in February 1959. With minimal financial returns Fairchild sold their interests in ArmaLite in 1962.
Featured in the first part of Vic’s special episode on the AR-10 is an original Armalite/Fairchild promotional film, originally filmed in 16mm, that dates from around 1958. While a version of this film has been shared online for a number of years it is grainy, washed out and of relatively low audio quality. Vic reproduced the very rare promotional sales film in the 1990s onto VHS (a process he explains in the video). He has managed to take an original VHS copy and digitally remaster it to regain some of the original’s clarity and detail.
The promotional film was originally used by salesmen to showcase the AR-10 to potential clients and features Hollywood-produced guns. Both Stoner and Charles Dorchester (ArmaLite’s production manager) are seen in the film demonstrating the AR-10. The rifle’s action, function and controls are explained and various variants, including rifle and light machine gun, are demonstrated. The demonstration segment included a sub-zero test, covering in sand and much and Stoner himself dumping 5 magazine’s through the rifle in quick succession. The promotional film concluded with demonstrations of firing rifle grenades and a belt-fed AR-10.
Vic concludes the first part of the AR-10 overview episode with an examination of an AR-10B rifle held by the Netherlands’ Nationaal Militair Museum. In the second part of the episode Vic will look at nearly a dozen AR-10 variants made by Artillerie Inrichtingen (A.I.) between 1957 and 1961.
Vic kicks off his series looking at the US Army’s ACR trials rifleswith a look at, not one but two versions of, Heckler & Koch’s advanced caseless ammunition assault rifle – the G11. This video is an introductory overview, we’ll be delving into the G11’s insanely intricate and wonderfully complex action in later videos!
There are few experimental weapons that have cultivated myth and reputation like Heckler & Koch’s G11. The product of decades of research and development into what was hoped would be the next evolutionary step in small arms design. The G11 was Germany’s attempt to combine advanced caseless ammunition with a weapon system which could increase the average infantryman’s hit probability. The G11’s action has three distinct modes of fire and uses a complex action and buffer/recoil system to achieve a high rate of controlled fire.
The program began in the late 1960s as part of a NATO initiative, however, it became a primarily Bundeswehr project and over two decades the design evolved substantially. The project sought to increase the hit probability of the individual infantryman. Heckler & Koch’s approach to this problem was the most radical. Working with Hensoldt to develop an integrated optical sight and with Dynamit-Nobel to create a new kind of ammunition.
Numerous studies and theoretical designs were worked up but by the mid-1970s the base design of what would become the G11 was cemented. The design team included Gunter Kastner, Dieter Ketterer, Tilo Moller and Ernst Wossner – all of whom are credited in H&K’s 1976 patent protecting the G11’s rotary action.
The G11 went through dozens of iterations throughout the 1970s and 80s, with the first firing prototypes ready by 1974. Both the design and the ammunition also went through a number of changes.
The revolutionary ammunition was developed by Dynamit-Nobel AG.
The 4.73x33mm round which was finalised comprised of a solid propellant material body which encased a primer, booster, projectile and a plastic nose cap. Dynamit-Nobel developed the High Ignition Temperature Propellant (HITP) in an effort to prevent accidental ignition (cook-off) of the ammunition’s outer propellant body.
The G11 fed from 45 or 50-round horizontal, single stack box magazines which fed rounds into the action at 90-degrees. The rounds were then rotated into alignment with the breech by the rifle’s action.
The rectangular shape of the Dynamit-Nobel ammunition was more efficient and better suited to storage than conventional circular rounds. The positioning of the magazine along the top of the weapon, parallel to the barrel, also in theory helped minimise the rifle’s profile and reduce encumbrance for the soldier equipped with the weapon.
The G11 is a gas-operated weapon with gas being tapped from the barrel, to cycle the rifle’s cylinder drive system, which rotated the breech through a series of cams and gears. At the heart of the G11 is a complex rotary action. Rotating actions themselves are not a new concept with the earliest dating back to the 17th century, such as the Lorenzoni system.
The G11’s rotating breech was patented in late 1976 by Heckler & Koch. While our initial video does not go into detail on how the G11 operates, we will be covering this in later videos, this article will explain the action in more general terms.
Below are two diagrams showing the internal layout and major components of the G11 from a March 1982 draft of the ‘Rifle, 4.92mm, ACR’ armourer’s manual (source). It shows the major assembly groups and also a component list for the breech assembly.
From the diagram we can see the various action parts which feed the projectile into the breech, lock the action and ignite the round. We can also see the counter-recoil system beneath the barrel.
The G11 used a counter-recoil buffer mechanism to allow high rates of burst fire. When firing three round bursts the weapon send the rounds downrange at a rate of ~2,000 rounds per minute, only when the last round has left the barrel does the barrel and action begin to recoil inside the stock along a central guide. When in sustained fire the rate of fire is closer to ~460 per minute.
The buffer spring below the barrel is compressed as the recoiling barrel and breech assembly moves. In sustained fire the buffer spring is partially compressed with each round, but in burst fire the buffer is compressed to its maximum hitting before the buffer housing (which is when recoil from the burst is felt by the operator), this is described as having the barrel and breech assembly ‘float’.
To ready the weapon to fire a magazine was loaded into the magazine channel on top of the G11, a magazine dust door, which automatically closed when unloaded, was depressed as the magazine was pushed home. The cocking handle on the left side of the butt was then actuated. The operator rotated the handle 360-degrees counter-clockwise until the weapon was cocked (essentially like winding a clock). The same process will eject any rounds left in the chamber once the magazine has been removed.
Gas tapped from the barrel cycles the cylinder drive system with gas pushing a piston back to act on a series of gears which rotated the rotary breech from horizontal to vertical to allow a new cartridge to drop into the breech. There was a vent for high pressure gas underneath the butt stock this prevented pressure build up and mitigated some of the thermal build up.
The G11 K1 was tested by the German Army in the late 1980s with adoption planned for the early 1990s. Heckler & Koch continued to develop the G11, entering the G11 K2 into the US Army’s Advanced Combat Rifle (ACR) trials alongside entries from Steyr, AAI and Colt [all of which we will examine in upcoming videos]. However, the fall of the Berlin Wall in 1989 and the collapse of the Soviet Union in 1991 meant that West Germany no longer had the huge amount of funds needed to field the G11. At the same time the ACR program ended inconclusively and the G11 project was finally abandoned.
The extreme complexity of the design, the inadequacy of the weapon’s ergonomics and its inevitably high production cost casts doubt on whether the G11 would ever have seriously been considered for widespread adoption. Regardless of this the G11 is a fascinating footnote in small arms history representing a false start along a technological avenue which, with the Lightweight Small Arms Technologies (LSAT) program, may still prove fruitful. Heckler & Koch and Dynamit-Nobel’s ambitious design marks one of very few serious and potentially successful attempts engineers to overcome the plateau that firearms technology is currently stuck on.
Stripping the HK G11
Matt recently had the opportunity to disassemble a G11 and get a look inside the action. In this special video and accompanying full-length article he explains how the rifle strips and how it works! Check out the video here.
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At the end of the Second World War the British Army had two primary infantry machine guns: the Bren light machine gun and the Vickers medium machine gun. These weapons had proved their worth, the Bren was especially well liked and the venerable Vickers continued to be a reliable workhorse.
In the late 1940s, the British Army recognised the Soviet threat to Western Europe. In 1947, Field Marshal Bernard Montgomery, the newly appointed Chief of the Imperial General Staff wrote a paper outlining rearmament plans based on intelligence estimates of how quickly the Soviet Union was likely to be ready for another full-scale war. Montgomery believed that Britain had just 10 years to develop new weapons and begin rearmament before the Soviet Union had recovered enough to launch an invasion of Western Europe. As such the British Army felt that rearmament needed to be complete by the late 1950s.
A number of large budget programmes were launched while small arms projects were also undertaken. These included the Infantry Personal Weapon programme which sought to develop a new intermediate calibre infantry rifle – the IPW programme later yielded Stefan Janson’s EM-2, a bullpup chambered in .280, which was briefly adopted as the Rifle No.9. The FN FAL was later adopted due to changes in political circumstances – a long, fascinating story for another article. The companion to the IPW programme was the development of a Sustained Fire Machine Gun also chambered in .280. The TADEN, a belt-fed derivative of the Bren firing the new .280 round was designed by Harold Turpin (‘T’), the Armament Design Establishment (‘AD’) and Enfield (‘EN’). With the abandonment of the IPW the TADEN was also abandoned but its design greatly influenced the later X11.
Another major small arms programme was the search for a new machine carbine (or submachine gun). This saw the testing of designs from Sterling, BSA and Madsen – with the Sterling finally adopted as the L2.
The other major small arms project was the programme to find a new section level machine gun. The German MG34 and MG42 had impressed the Allies during the war, so much so the US went as far as to clone it with the T24. After the abandonment of the EM-2 and TADEN machine gun the British issued a new specification for a lightweight sustained fire machine gun, chambered in the 7.62x51mm round recently adopted by NATO, in the mid-1950s.
The design team at the Royal Small Arms Factory at Enfield developed a belt-fed derivative of the Bren light machine gun. The X11 series of prototypes sought to convert the Bren’s proven design into a weapon capable of sustained fire. The X11 made a number of changes to the Bren included the addition of a detachable butt/grip/trigger assembly which could be swapped for a pair of spade grips and a paddle trigger for static sustained fire from a tripod. This resulted in the pistol grip being located much further back than the traditional Bren’s.
It appears that during the mid-1950s British military parlance described the General Purpose Machine Gun as a Sustained Fire Machine Gun (SFMG). From the available photographs it appears that the L4 and X11 use the same barrel with its distinct flash hider. The receivers of all the prototypes appear to be milled to attach the optical long range sight seen above.
The main drawback with the X11 was its feed mechanism. The feed slide was indexed by a rotating vertical feed shaft which was driven by the gas piston’s recoil. This created a considerable amount of friction within the action. It had the effect of causing failures to feed during adverse conditions testing and elevated firing tests. A series of four X11 prototypes were developed with Harold Turpin (co-designer of the STEN gun and later TADEN) working on the new gun. Each prototype appears to have a sightly different trigger configuration. The most interesting of these is a two-finger double-crescent trigger reminiscent of the MG-34’s – from the photographs it appears that the conventional selector lever, used in the X11E2, was replaced with a fire-selector system similar to the MG-34’s (upper crescent – semi-auto, lower crescent – full-auto). However, the trigger of the example of the X11E4 examined by Vic (serial number #11) was fully automatic only, despite its crescent shape.
Below are photographs of examples of the three types held at the Royal Armouries:
The X11 was tested against the M60, French AA-52, Swiss MG51, Danish Madsen-Saetter, German MG-3, and the Belgian FN MAG. The FN MAG, designated the X15E1 by the British, fared best in the trials with the X11 coming second due to its feeding issues. In January 1958, the British abandoned the X11 and moved to adopt the X15E1 general purpose machine gun, negotiating a license for its manufacture. The weapon was finally adopted as the L7A1 in 1961, with production at Enfield beginning in 1963. It seems that the Birmingham Small Arms Company were a latecomer to the competition having developed the another belt-fed Bren gun derivative known as the X16.
The Bren did continue in service after the switch to 7.62x51mm. In 1954, before beginning work on the X11, Enfield had developed the X10E1. Taking a Canadian manufactured 7.92x57mm Bren breech block and converting it to cycle the new round. The X10E1 was formally adopted as the L4. The L4 remained in service, alongside the L7, into the early 1990s. The L7 GPMG continues to be used by the British Army.
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By the Autumn of 1940, Nazi Germany controlled most of mainland Europe, France had surrendered, and the British Army had been forced to evacuate the continent and in the process had lost much of its arms and equipment.
Arms production in Britain was ramped up in order to arm the returning troops and the new units being formed to defend against the imminently expected German invasion. Existing designs like the Bren light machine gun and the Lee-Enfield Rifle were simplified to increase production however new options were also examined. The cheap, quickly manufactured STEN submachine gun was introduced and calls were made for a simplified light machine gun which could be made in any machine or workshop with simple tooling. Even before the fall of France the British Ordnance Board sent out a memo in June 1940, requesting a light machine gun which could be produced in garages and smaller workshops throughout Britain in the event that the Royal Small Arms Factory at Enfield was bombed.
In December 1940, the Chief Superintendent of Design outlined a light machine gun based on the Lewis Gun’s rotating bolt, which fed from Bren gun magazines.
The Birmingham Small Arms company (BSA) were approached to develop a design. BSA tasked their chief designer, Henry Faulkner, with the project. Members of the British Army’s Ordnance Board, however, began to question the decision to have an established manufacturer build a prototype for a gun that was supposed to be assembled in small ad-hoc workshops. As a result the contract was cancelled, however, BSA and Faulkner persisted anyway.
Faulkner, with the help of Roger Wackrow, came up with a weapon which later became known as the BESAL. The design was developed to be simple, cheap and quick to manufacture. The standards of finish were significantly lower than those of the standard Bren then in production. The plan was to issue the BESAL in the event Britain’s armed forces found themselves engaged in a last ditch defence with German invasion either imminent or already underway.
Faulkner’s design was chambered in .303 and fed feeding from standard Bren gun curved box magazines. It used a basic trigger mechanism, a simple pressed gas cylinder and a body held together by pinning and spot welding. The first prototype had a folding but non-adjustable bipod and a skeleton butt stock with a wooden insert. With the manufacture of barrels expected to be a bottleneck to the weapon’s production it was suggested that the spare barrel issued with each Bren gun be recalled for use in the new BESAL. This clearly illustrates just how desperate the situation was expected to be. The first prototype BESAL was ready by late 1941, and testing began in March 1942. The BESAL proved to be reliable and effective during trials.
Faulkner’s design went through a number of iterations but the gneral design had been finalised by May 1942 when BSA, Faulkner and Wackrow filed three patents protecting the design. The principle feature of the later BESAL patterns was the use of a cocking system which saw the operator push the pistol grip forward to catch the bolt, and then pull it to the rear to cock the weapon. This is a system that was later seen in the Czechoslovakian Vz 52/57, 59 series and the Finnish KVKK-62 general purpose machine gun.
Iterations of the BESAL:
(Artists impression of 1st BESAL prototype – from Dugelby’s Bren Gun Saga)
Right side cocking handle
Simple fixed peep sight
Non-adjustable bipod mounted on the receiver
(Photograph of a 2nd Pattern BESAL with a pan magazine, note the right-side cocking handle – from Dugelby’s Bren Gun Saga)
Bipod moved to front of the gas tube
Universal magazine adaptor fitted for Bren and Motley Pan magazines
Full wooden stock – similar in profile to the Lewis Gun’s
Disassembly knob introduced
(Our photograph of a 3rd Pattern BESAL)
Pistol grip cocking mechanism replacing the conventional cocking handle
(Photograph of a 4th Pattern BESAL, note the selector on the pistol grip – from Dugelby’s Bren Gun Saga)
Introduction of a selector switch on the left side of the weapon’s pistol grip
In August 1942, BSA submitted the 3rd Pattern Prototype for trials. It was extensively tested between September and November 1942. On 6th January, 1943, BSA renamed the BESAL the ‘Light Machine Gun, Faulkner, 0.303-In Mk1’ in order to prevent confusion with the 7.92x57mm BESA machine gun used in some British tanks. The BESA, also produced by BSA, used a similar pistol grip cocking mechanism. We hypothesise that the the BESAL’s name might come from the BESA, meaning BESA-Light. This, however, is unconfirmed.
It seems that over time as BSA and Faulkner improved and refined the design the BESAL ceased to be a cheap, simple, quickly-made alternative to the Bren. Instead it appears that BSA hoped the weapon might be adopted as a somewhat cheaper substitute standard to the Bren. Final testing of the BESAL were held in March 1943, but by now the weapon’s original purpose had been made defunct by the huge increase in Bren manufacturing capacity. By 1943 the Bren was in production on four continents: at Enfield in the UK, at John Inglis in Canada, at Ishapore in India and Lithgow in Australia. Inglis alone was producing 10,000 Brens a month by 1943.
With the need for a new light machine gun gone the BESAL project was cancelled in June 1943. BSA produced an estimated 20 guns, of various patterns, during the BESAL development project. Today, it is believed that only a handful remain.
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Length: 118.5cm (46.6in)
Weight: 9.7kg (21lb 8oz)
Barrel Length: 56cm (22in)
Action: Gas operated, short recoil
Feed: 30-round Bren box magazine or 100-round Motley pan magazine
Cyclic Rate: 600rpm
The Bren Gun Saga, T. B. Dugelby (1999)
Bren Gun, N. Grant, (2013) Military Small Arms, I. Hogg & J. Weeks (1985)
Modern Small Arms, F. Myatt (1979)
‘Improvements in or relating to gas-operated automatic firearms’, GB572925, BSA, H. A. Faulkner & R.D. Wackrow, 30/10/1945, (source)
‘Improvements in or relating to automatic firearms’, GB572926, BSA, H. A. Faulkner & R.D. Wackrow, 30/10/1945, (source)
‘Improvements in or relating to automatic firearms’, GB572924, BSA, H. A. Faulkner & R.D. Wackrow, 30/10/1945, (source)