#prototype guns

McClean Prototype Automatic Rifle

During the early 1900s Samuel McClean had developed a large, truck-mounted, 37mm auto-cannon but following the failure of this project McClean began development of a rifle-calibre machine gun. The result was a series of complex designs which never fully matured. 

McClean, a medical doctor by training, had previously developed a series of firearms including a semi-automatic pistol, rifles and a shotgun. He is perhaps best known for designing what would eventually become the Lewis Gun, he was certainly a talented and prolific inventor with over thirty, predominantly gun related, patents to his name by 1920. 

This gun, however, is one of McClean’s attempts to develop a viable automatic rifle. Believed to date from 1918-19, it is certainly smaller and less complex than his earlier water-cooled prototypes. The gun pictured above is incomplete but does have a wooden butt-stock and front grip. The gun has a pair of triggers, one for semi-auto and the front trigger for fully-automatic fire. What isn’t present is the weapon’s magazine. When examining the photographs above its worth noting that the gun itself has been rendered inoperable by cutting away part of the receiver, to fulfil US laws regarding machine guns.

A couple of contemporary photograph are, however, reproduced in Henry Chin’s book on machine guns. Chin’s book remains the best available resource concerning this prototype.

In the photograph above we see Samuel McClean firing his automatic rifle from a bipod. We can see that the magazine is a large circular drum-like assembly which surrounded the receiver of the weapon. To load the magazine the weapon itself musthave been passed through the centre of the magazine until it interfaced with a ratchet system just ahead of the chamber. As a result the gun feeds from the top of the receiver and ejects spent cases from the left. A large magazine release catch with a hook is just in front of the trigger guard. According to Chin the operating mechanism of the weapon was very similar to McClean’s auto-cannon. 

McClean’s 1905 patent for his auto-cannon showing the gun’s gas operating system. (source)

Like the auto-cannon the automatic rifle uses a large number of small interrupted-threads to lock the rotating bolt in battery. Below the barrel is a gas system, with a piston inside a large gas cylinder with a main spring inside as in the larger cannon. 

According to Chin the gun was demonstrated for the US Navy in May 1919 at the Naval Air Station in Anacostia, D.C. Chin notes that while the weapon operated satisfactorily the Navy showed no interest in the design with the M1918 Browning Automatic Rifle already in service and World War One over their was no need for another automatic rifle. 

Sources:

Images Source

The Machine Gun, G.M. Chinn, (1951) Our friend Ian over at Forgotten Weapons has also taken a look at the gun and shows some of the working parts.

John Browning's 1892 En Bloc Lever-Action Prototype

The 1890s was one of John Browning’s most prolific periods. He developed a whole host of firearms designs which never saw production. Many, like this one, were purchased by Winchester but never saw the light of day. This fascinating rare prototype, currently on display at the Cody Firearms Museum, feeds from a 5-round en bloc clip rather than a tube magazine.

Check out this week’s Armourer’s Bench video:

It’s an elegant design and one of many that beg the question ‘why wasn’t it manufactured?’ Its a pleasure to bring some attention to another of Browning's lesser-known, forgotten designs. I hope you enjoy the video.

Rheinmetall Rh4

The CETME, and by extension the G3, had never been designed to fire a powerful round like 7.62x51mm NATO. CETME and Heckler & Koch had worked hard to reinforce the rifle’s receiver and introduce the use of high carbon steel. 

Rheinmetall, who along with H&K, had won the contract to manufacture the G3 for the Bundeswehr developed a variant of the G3 chambered in the Soviet 7.62x39mm intermediate cartridge. The Rh4 used a long-stroke gas piston system believed to be designed by Henk Visser, however, contemporary patents suggest Theodor Loffler worked on on the gas system. Instead of using Ludwig Vorgrimler’s roller-delayed blowback action, the Rh4 fired from a locked breech with the rollers only unlocking once the projectile had passed the gas vent. 

Two prototype Rh4′s are believed to have been manufactured. They fed from 30-round AK-pattern magazines and had a distinct hand guard which attached to the receiver by a pin just in front of the magazine housing. Rheinmetall struggled to get the G3 into full production and H&K took over prodction later developing their own intermediate cartridge versions of the G3: the HK32 chambered in 7.62x39mm, which never went into production, and the more successful 5.56×45mm HK33 family. 

Sources:

Images: 1 2 3 4 5

The World's Assault Rifles, G.P.Johnston & T.B. Nelson, (2016)

Small Arms of the World, W.H.B. Smith, (1983)

High Standard T3

The programme to develop a new US Military sidearm began in 1947 at the request of the US Army Air Force. In 1948 Colt and High Standard were contracted to develop a new lightweight 9x19mm sidearm to replace the Colt M1911A1. 

Initially the pistols were not to exceed 7-inches (17.7cm) in overall length and be no heavier than 25 ounces (0.7kg) unloaded. The military requested that the pistols use a blowback action and have a folding trigger guard to allow use with thick gloves. An initial request for the pistols to incorporate a ‘squeeze charger’ system were quickly dropped.

The US Army approached several companies to submit bids to develop the new pistol. High Standard, Colt and Harrington & Richardson all submitted bids, while Ithaca declined to bid and Harrington & Richardson’s bid was turned down. The military accepted Colt and High Standard’s bids and contracted them to begin development of the new pistols. The Ordnance Corps designated High Standard’s submission the T3 and Colt’s the T4. 

Several batches of the T3 were made each with incremental improvements. The position of the safety and magazine releases were altered with each iteration of the T3. The prototype and first batch of pistols had heel magazine releases while the second batch placed the magazine release on the frame. The first prototype High Standard pistol (see image #1) did not yet have the pivoting trigger guard which would become standard in the later experimental models. The second batch of pistols had a thicker trigger guard than the first set and a repositioned enlarged safety (see images #5 & #6).

In June 1948, High Standard submitted the first batch of three T3 test pistols. The T3 had a frame made from 75ST aluminium and a steel frame. It used a straight blowback action but had annular grooves cut into its chamber which caused the cartridge case to expand, in theory slowing the rearward travel of the slide and the opening of the breach. This was believed to mitigate some of the gun’s sharp recoil impulse. Otto-Helmuth von Lossnitzer, technical director of Mauser Werke, designed this system. Interestingly, at least one, presumably blowback, prototype had a slide-mounted muzzle break, possibly in an attempt to prevent the breech opening too early in the cycle. This feature seems to have been subsequently abandoned.  

To fulfil the military’s specification for firing while wearing gloves George Wilson designed a pivoting trigger guard which neatly folded into a recess in the frame. In addition to allowing the user to operate the pistol while wearing thick gloves High Standard’s design also incorporated a spring-loaded plunger. This plunger was pushed into place against the trigger when the user pivoted the trigger guard into the open position and latched to the pistol’s frame. The plunger impinged against the trigger making the trigger pull heavier. in theory this would compensate for the operators lack of sensitivity caused by their gloves.

Figures from George Wilson’s patent for the T3′s Pivoted trigger-guard (source)

The first batch of T3s used a double action trigger and had a single stack magazine holding 7-rounds - on par with the M1911A1. Testing of this first batch of pistols took place at the Aberdeen Proving Ground in May 1949. Several failures occurred and testing identified a number of problems. One pistol's hammer broke due to inadequate heat treatment which left it brittle. A number of failures to feed also occurred with cartridges upending in the breech. High Standard rectified with the addition of a guide shelf at the top of the chamber to guide the cartridge into the chamber.  

In April 1950, High Standard were paid $20,000 (approximately $200,000 today) for a second batch of three improved pistols. These were to meet the Ordnance Corps' revised specification which allowed the weapons to weight up to 29 ounces and requested a 13-round minimum magazine capacity. The second batch of T3s abandoned the annular chamber grooves and had a redesigned frame to take the larger magazines. The Springfield Armory tested the new batch of pistols in March 1951, the 75ST aluminium frames suffered a series of failures at stress points - probably due to the enlarging of the frame. The Ordnance Corps recommended that High Standard make the frames from heat treated 14ST aluminium, reinforce and weak points in the frame. High Standard designed the second batch's controls to be more similar to the M1911 and the trigger was redesigned for a better double action pull. Interestingly, High Standard independently developed the annularly grooved chamber and submitted a spare barrel and recommended the Ordnance Corps test it.

In April 1951, a preliminary report noted the second batch of refurbished T3s were unsatisfactory, suffering 19 failures in 150 rounds. The hammer of one pistol broke and the Ordnance Corps recorded further failures to feed. The army returned the pistols to High Standard. High Standard refurbished the pistols and a second test at Springfield was held in September. Testing officers recorded seven failures with further misfeeds and discovered stress fractures in all three of the pistols.

The army ordered a third batch of pistols with the design reverting back to a single stack magazine holding 8 or 9 rounds.This was a reversion to the first batch of T3s which had fared better in testing. Despite this, during testing in November 1952, the pistols suffered numerous failures and an excessive number of malfunctions. During an endurance test the magazine release broke 35-rounds into the test and the slide stop malfunctioned. The second pistol’s hammer cracked and suffered extraction problems. The pistols were again returned to High Standard to fix these issues. A final trial took place in March 1953, however, the pistols were again found to be unsatisfactory and the Ordnance Board officially cancelled the T3 programme.

In his book, Random Shots, Ray Rayle recalls that in the summer of 1955, the US Army prepared a solicitation pamphlet to release to manufacturers on the 4th July. The pamphlet was to announce the Army’s plan to adopt a new 9x19mm handgun with the successful design winning an award of $150,000. While initial testing had taken place and the designs from Colt and High Standard had shown initial promise, the Army wanted to examine pistols from manufacturers around the world. Rayle explains that the launch of the pamphlet and the official pistol trials program were cancelled when the Deputy Chief of Staff for Logistics refused the $150,000 of funding on the grounds that sidearms were seldom used and that existing stores of M1911A1s were more than adequate.   

Sources:

Images: 1 2 3 4 5 6

‘Pivoted trigger-guard for firearms’, US Patent #3106795, G.A. Wilson, 15/08/63, (source)

High Standard T3 pistols in the Springfield Armory’s Collection: 1 2 3 4

US Military Automatic Pistols 1945-2012, E. S. Meadows, (2013)

My thanks to Nathaniel F for his help accessing Meadow’s book.

Evelyn Owen’s First Prototype

Chambered in .22 Short, Evelyn Owen’s first prototype was an ingenious homemade weapon built in 1938. Owen had a profound interest in firearms and enjoyed tinkering. This first prototype shares little in common with his more refined later submachine gun designs. The prototype’s stock and barrel appear to be borrowed from a .22 calibre civilian rifle while a crudely cut and fashioned steel cover enclosed the weapon's action.  

Owen ingeniously made the drum magazine from an automobile crankshaft’s harmonic balancer. Owen drilled holes into the balancer to hold each individual cartridge essentially creating a revolving cylinder with individual chambers (see image #2). The magazine/cylinder held 44 .22 short cartridges. 

The prototype lacked a traditional trigger, instead Owen used simple a thumb trigger made of spring steel which held the bolt back when cocked. Depressing the trigger released the bolt allowing the weapon to slam-fire. In this layout the pistol grip is actually the front grip. The magazine/cylinder was apparently turned by a piece of flat spring steel attached to the receiver (see images #3 & #4). The prototype lacks any kind of safety mechanism.

In May 1939, Owen travelled from Wollongong to Sydney to present his prototype at Victoria Barracks in the hopes of interesting the Australian military. The Australian Army turned Owen and his design away. A year later Owen enlisted in the Australian Imperial Force and he stored the weapon in the garage of a house rented out by his father. 

The man renting the house, Vincent Wardell, discovered the prototype. Wardell happened to be the manager of Lysaght metal works in Port Kembla. He encouraged Owen to demonstrate the weapon and wrote to the Australian government. The weapon garnered enough interest to allow Owen to continue developing his design at the Lysaght factory. After a series of developmental prototypes the Australian Army tested Owen’s refined submachine gun and adopted in 1941.  

Sources:

Images Source

The Australian Owen SMG, Forgotten Weapons, (source)

Wardell, V. A. (2000). "Owen, Evelyn Ernest (1915–1949)". Australian Dictionary of Biograph (source) 

Experimental .45 ACP Owen Submachine Gun 

Evelyn Owen chambered his third prototype in .45 ACP. His first workshop prototype, built at the Lysaght factory in Port Kembla, chambered .32 ACP. The move to .45 ACP was no doubt influenced by the use of the Commonwealth force’s use of Thompson submachine guns. 

The third model was the first to position the magazine on top of the weapon, rather than the left-side feed of the .32 ACP prototype. This top-feed layout would be used by all subsequent prototypes and the final 9x19mm production gun. The vertical magazine had the benefit of being gravity assisted, helping feed reliability. 

Owen and his team built at least two .45 ACP guns, the first pictured above appears to be an early model as it shares the same pistols grip shapes, butt stock profile, magazine release and trigger assembly with the earlier .32 ACP prototype. However, the location of the cocking handle has been moved to the top of the receiver tube, spring clips holding the barrel in place are replaced by a screw thread beneath the receiver and the overall length of the receiver has been reduced. The second prototype featured has a trigger assembly more similar to the final adopted weapon, both its plastic grips also have the finger-grooves seen on later guns. The third model prototypes are the first to have the recognisable Owen profile. 

The third model was followed by experiments to chamber the weapon in the British revolver cartridge .38-200. This necessitated a curved magazine due to the tapered and rimmed cartridge. This was tested as it was the Commonwealth’s standard cartridge. The final prototype, like the British STEN, chambered the ubiquitous 9x19mm round. Following testing of all of the prototypes during 1941, the Australians adopted the Owen in 9x19mm. The Australian War Memorial centre holds examples of all of the prototypes.

Sources:

Images: 1 2 3 4 

Experimental Second Model .32 ACP Owen Submachine Gun 

Developed by Australian Evelyn Owen, the Owen Machine Carbine became one of the most reliable and effective submachine guns of the Second World War. The prototype pictured above is an early factory prototype chambered in .32 ACP, rather than the final 9x19mm. 

Owen began work on his design in 1938, hand building a .22 calibre prototype with an unusual drum magazine (see below). As he further developed his weapon at the Lysaght factory in Port Kembla the design evolved. The placement of the magazine changed a number of times and Owen built prototypes chambered in .32 ACP, .38-200 .45 ACP and 9x19mm. 

The .32 ACP prototype pictured above loaded from the side, unlike the final Owen Gun which had a top-mounted magazine (see image #4). The 30-round magazine fitted into the left side of the receiver and was angled slightly down and to the rear. Presumably this was in an effort to aid reliable feeding.

Owen’s prototype .22 calibre Submachine Gun (source)

The Australian army requested a centrefire prototype chambered in .38-200, a rimmed cartridge. The engineers at Lysaght recognised this would pose problems with reliable feeding. Instead they sidestepped the .38-200 stipulation and in just three weeks developed a prototype chambered in the rimless .32ACP cartridge instead. Ingeniously the Lysaght engineers utilised a section of .303 SMLE barrel. The .32 ACP prototype was tested for the first time on the 30 th January, 1940.

The prototype has some of the later features of the production model with two finger-grooved pistol grips and a tubular receiver. The butt and trigger mechanism could be released by a spring clip on the right of the receiver. Similarly the barrel was also held by a spring clip but could be held in place by a threaded sleeve. These spring clips were later eliminated from the design. The Owen gun's receiver was later shortened but retained the distinctive compensator.

A later prototype Owen Gun chambering 9x19 (see image #4) was successfully trialed in 1942 and adopted by the Australian military. Between 1942 and 1945 Lysaght produced approximately 45,000 Owen Guns. They proved extremely reliable and remained in service into the 1960s. They saw action with Australian and New Zealand troops during World War Two and later in Korea and during the Malayan Emergency, Indonesian Confrontation and the Vietnam War.

Sources:

Images: 1 2 3 4

Owen’s Australian Patent for his Machine Carbine, #115,974, 19/02/43, (source)

The Australian Owen SMG, Forgotten Weapons, (source)