Our thanks to the collection that holds the G11 for the privileged and nerve-wracking opportunity to field strip it and take a look inside. If you’d like to know more about the history of the G11’s development you can check out our video and full blog on it here. Vic has done a great series of videos looking at the G11 and the other prototype rifles from the US Army’s abortive Advanced Combat Rifle trials – you can find those here.
In this blog we’ll take a closer look at some of the G11’s components, for a demonstration of dissassembly and and explanation of how the rifle works in principal check out the video above.
Firstly, lets take a look at the exterior of the rifle. The weapon has a box-like polymer coated outer shell. The shell is made up of three parts, with the butt assembly and forend locking into the centre assembly which includes the pistol grip, trigger mechanism and optical sight. The forend and butt are locked into the centre assembly by plastic locking tabs. While stiff and somewhat difficult to depress the tabs are reportedly prone to breaking.
Before we look at the G11’s internals lets take a look at the shell components. Here we can see the inside of the forend, we can see a metal (aluminium I believe) barrel tube into which the barrel slides.
Below is a photograph of the rear of the centre assembly looking forward, the small white circle (sadly slightly out of focus) is the bushing the barrel protrudes through into the forend.
Next we have a view of the inside of the rifle’s butt assembly. Note the scuff marks on the inside where the centre assembly has scrapped the plastic. We can also see the locking tab windows which are on the top and bottom of the butt.
Inside the butt we can see the ‘toothed wheel’ and ‘sealing gear’ which are turned when the cocking piece is rotated. These plastic pieces act directly on the action. Behind that is the gas escape valve, which will tap off excess gas if over pressure problems occur with the rifle.
The first step to disassembling the G11 is ensuring the weapon is clear by pushing the cleaning brush up into the breech.
Lets now take a look at the rifle’s action up close, below we can see the G11 with its forend and butt assembly removed. Next to it is the breech cylinder and control disk.
Here are some photos of the action from various angles:
Here’s some close ups of the breech cylinder and control disk:
Here are some close ups of the various parts of the action:
According to the 1989 armourer’s manual, provided for the ACR trials, the G11 is made up of a total of nearly 450 individual parts. 144 of those make up the G11’s breech assembly.
With the breech and barrel assembly removed from the centre assembly here’s a diagram I put together showing most of the component parts of the G11’s action:
Next lets take a look at the G11’s barrel assembly with its recoil management system and gas piston:
Finally, here’s a photo of the G11 broken down into its major component assemblies: magazine, forend, centre assembly breech & barrel assembly and butt stock:
HK G11- ACR. Armourer’s Manual for Maintenance of Repair of Rifle, 4.92mm, ACR, March 1989 (source)
Today we’re examining an intriguing firearm with a fascinating history. It is difficult to understate the potential importance of the Curtis Rifle. Despite being designed in Britain in the 1860s the firearm gained more notoriety when it was offered as evidence in a legal battle between the Winchester Repeating Arms company and Francis Bannerman. What makes the firearm most noteworthy, however, is its fundamentally unconventional layout. Designed by William Joseph Curtis in the mid-1860s, it is arguably one of the earliest ‘bullpups’ and almost certainly the first repeating bullpup.
For the purpose of this article it would be wise to first define what a bullpup actually is. It can be defined as a weapon with a somewhat unconventional layout which places the action and magazine behind the weapon’s trigger group. This has the benefit of maintaining a conventional rifle’s barrel length while making the overall length of the rifle more compact.
Bullpup rifles became popular with a number of militaries around the world during the 1970s and 1980s – namely the Austrian Steyr AUG, the French FAMAS and the British SA80, and more recently with rifles from China and Singapore as well as the Tavor series of rifles from Israel.
The bullpup, however, dates back much further with some argument to be made for the first firearms to utilise the concept being 19th century percussion target shooting rifles. The earliest military bullpups date to the beginning of the 20thth century, these include a rifles designed by Samuel McClean, the initial designer of the Lewis Gun, patented in 1896 (US #723706), by Major Philip Godsal (US #808282) and a carbine developed by James Baird Thorneycroft in 1901. Thorneycroft subsequently worked with Moubray Gore Farquhar and Arthur Henry Hill to patent a refined version of the carbine in 1905 (US #827893). While the Thorneycroft was tested by the British army it was rejected due to ergonomic and reliability shortcomings.
William Curtis’ design, however, predates all of these. Patented in Britain on 10th July, 1866, Curtis is listed by the London Gazette as a Civil Engineer. His design is unlike anything that had been seen before. Based on a slide-action with a drum magazine, it was placed over the shoulder – much like a modern shoulder-fired anti-tank weapon.
Curtis’ rifle is probably the very first bullpup magazine rifle, one of the earliest to have a drum magazine (an Italian, Marco Antonio Francois Mennons, patented an earlier design for a drum magazine in March 1862, GB #637) and also an early striker-fired design. Clearly a design well ahead of its time and radically unconventional.
This unconventional gun’s designer was born in Islington, London in 1802, as a civil engineer he worked on Britain’s rapidly growing railway network. He died in 1875, placing the development of his rifle nearer the end of his life. With hindsight Curtis’ design clearly had revolutionary potential but it appears that his concept was never taken up. It appears that he only patented his design in the United Kingdom. If not for a corporate lawsuit on another continent, decades later, then it is possible Curtis’ design, like so many others, would have slipped into historical obscurity.
Francis Bannerman vs. the Winchester Repeating Arms Company
In 1890, Francis Bannerman VI, a successful entrepreneur specialising in junk, scrap and later surplus, purchased the Spencer Arms Company and the rights to their patents. The company had been founded by Christopher Miner Spencer, designer of the Spencer Rifle, they produced the first commercially successful slide or pump-action shotgun. This pump action shotgun was designed by Spencer and Sylvester H. Roper and patented in April, 1882 (US #255894). Bannerman continued producing the shotgun as the Bannerman Model 1890, however, in 1893 the Winchester Repeating Arms Company, introduced the John Browning-designed Model 1893 pump shotgun (US #441,390).
In response in October 1894, Bannerman filed a law suit against the Winchester Repeating Arms Company claiming that the slide/pump actions used by Winchester’s Model 1890 and new Model 1893 shotgun infringed on the patents that he owned.
He called for the court to force Winchester to halt production and claimed $10,000 in damages and royalties for the sale of guns which he believed infringed his patent. Winchester temporarily halted production of the Model 1893, in the meantime Bannerman continued producing and improving his shotgun introducing the 1894 and 1896 models.
Various contemporary newspaper reports suggest between 100,000 and 500,000 people were directly interested in the case as ordinary owners were liable under the conditions of Bannerman’s suit.
Winchester dispatched George D. Seymour to Europe to scour the French and British patent archives for any patents for similar actions that had been filed there before those now owned by Bannerman. Winchester discovered four patents: three British and one French. The earliest of these was Alexander Bain’s patent of 1854. Two more patents held by Joseph Curtis and William Krutzsch were found, dating from 1866. The later French patent was filed by M.M. Magot in 1880. All of these designs, including the Curtis we are examining here, never progressed beyond the development stage and were largely forgotten until rediscovered by Winchester.
Winchester claimed that these earlier designs invalidated Bannerman’s patent claims. To illustrate their defence Winchester decided to build working models of each of the designs, breathing life into long forgotten patent drawings. This must have been a major engineering task as the patent designs would not have had all the information needed to produce a working model.
In 1895-96 Winchester engineers, including T.C. Johnson, assembled working models of each of the designs to prove their viability. These were tested and Winchester’s lawyers took them into court and submitted them as evidence, even offering a firing demonstration. The court declined the demonstration and made its decision on June 27th 1897. Judge Hoyt H. Wheeler of the United States District Court for the Southern District of New York ruled in favour of Winchester and threw out Bannerman’s suit.
Winchester had produced some 34,000 Model 1893s before, in November 1897, they introduced the improved Model 1897 which proved to be hugely popular on both the civilian and military markets. Bannerman unveiled a final shotgun, the Model 1900, but production ended in the early 1900s.
Curtis’ Unconventional Design
Curtis’ design encapsulates a number of features which, in 1866, were unheard of and arguably revolutionary. Not only is it probably the first magazine-fed repeating bullpup but it also uses a drum magazine, something that would not see substantial military use until the First World War. It has a folding shoulder support or stock, uses a striker fired action and makes use of self-contained ammunition.
The Curtis’ rifle is placed over the top of the user’s shoulder with a folding leather strap which fits into the shoulder pocket. Curtis’ original patent also suggests a fixed hook and strap. The user then grasps the loop near the muzzle with their support hand and the trigger and bolt handle with their other hand. Novel, but not the most ergonomic of designs.
The magazine appears to hold at least 13 or more rounds according to the available patent and Winchester’s engineering drawings. The magazine is fixed in place and rounds appear to have been fed into it through the loading/ejection port on the left side of the weapon. This would have also put spent cases being ejected right next to the user’s neck. Curtis’ patent explains that the magazine has a spring inside which has a length of string attached to the top of it which the user can pull back to depress it and allow cartridges to be loaded into the drum. The magazine has a single stack or loop of cartridges. Once loaded the string can be released, allowing the magazine spring to push rounds into the action.
The Curtis rifle’s action appears to lock at the front of the weapon with the bolt handle acting on a hinged, spring-loaded, locking piece or flapper which dropped into place when locked. To unlock the action the bolt handle was sharply pulled to the rear which pushed the locking piece out of engagement and unlocked the action allowing the operating rod to be cycled.
The weapon’s chamber appears to be just forward of the centre of the drum magazine with the striker assembly located behind it. To operate Curtis’ rifle the magazine was loaded and then the user had to unlock the action by pulling the bolt handle backwards. This then allowed the operating rod to be pulled backwards, like a pump action, which pushed the bolt and striker assembly to the rear, cocking the striker, the bolt handle was then returned forward and locked back into position. This chambered a round ready to be fired.
The trigger at the front of the firearm is connected to the striker assembly by a long length of wire. When pulled the wire becomes taught and trips a sear to release the striker, firing the weapon.
Originally Curtis’ patent describes how ‘small punches’ on the bolt face would pierce the cartridge base during firing to enable the spent case to be extracted once the action was cycled. From Winchester’s engineering drawings, however, it appears they replaced this with a more reliable and conventional extractor at the 7 o’clock position of the bolt face.
Given that the weapon would have fired black powder cartridges it is unclear how well the rifle would have faired with sustained firing. The drum magazine would have been susceptible to jamming as a result of powder fouling. This, however, would not have been an issue for Winchester later version of the rifle.
But the Curtis has one more interesting surprise. The original 1866 patent also includes what might be one of the earliest descriptions of a gas operated firearm. One of the most fascinating sections of Curtis’ original patent details how the rifle might have been adapted for gas operation:
“An arrangement is shown in Fig.10, in which the rod G is dispensed with; in this case the barrel may be shorter, not projecting beyond the shoulder; the butt is similar. The breech may be opened automatically by the powder gases, which pass by an opening in the barrel to a cylinder with which works a breech operating plunger.”
Curtis does not go into further detail but he is clearly describing a piston-driven, gas operated system. The patent drawing also depicts an alternative tube magazine instead of the drum magazine.
It is unknown if Curtis ever put his theory to the test and developed his gas system idea further. It is tempting to wonder if, in 1895 when Winchester were assembling their model of the Curtis, if John Browning or William Mason, who were also developing their own gas operated systems at the time, were aware of Curtis’ idea from 30 years earlier. As such Curtis’, admittedly vague, gas system pre-dates the first patents on gas operation by just under 20 years.
Action: Slide action
Calibre: .32 Winchester Centre Fire
Feed: ~12 round drum magazine
My thanks to the Cody Firearms Museum at the Buffalo Bill Center of the West for allowing me to examine and film the Curtis. Special thanks to the CFM’s assistant curator Danny Michael for making extra time to open up the case where the rifle Curtis is on display so we could examine it and for also sharing Winchester’s technical drawings and other records.
Thanks also to David Minshall of Research Press.co.uk for his assistance finding Curtis’ original British patent abridgement and to John Walter for digging up some additional information about Curtis’ life.
‘Winchester Suit Decided’, The Times (Philadelphia), 27th June, 1897
‘Recollections of the Forming of the Pugsley & Winchester Gun Collections: A Talk Given by Mr. Edwin Pugsley at the New Haven Meeting of the AS of AC’, September, 1955.
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.
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)