In this episode we bring you our first live fire and slow motion footage! Matt had the opportunity to fire a British L2A3 Sterling submachine gun and Vic captured some great video. The Sterling was adopted by the British military in 1954 and standardised as the L2A3 in 1956.
Designed by George Patchett, at the Sterling Armaments Company, development began towards the end of the Second World War. After a decade of development and testing the British Army adopted the Sterling. It remained in service into the 1990s and Sterling produced and sold the gun overseas until the company closed in the late 1980s. Licensed versions of the Sterling were made in Canada and production continues today in India.
While the Sterling Armaments Company, the original developers and manufacturer of the gun, produced L2A3s for the government and the commercial market most of the British Army’s Sterlings were made by the government owned Royal Ordnance Factory in Fazakerly near Liverpool.
The gun featured in the video is a Fazakerly-made British Army L2A3, the magazine is also of the slightly simplified government pattern.
In this episode we look at the firing cycle of the L2A3 and how the weapon works. The Sterling uses a standard blowback action and this footage shows it firing in semi-automatic. We can see the breech block travel forward, strip a round from the magazine and chamber it. The round is fired and the breech block then travels rearward again before repeating the cycle.
In future videos we will discuss in-depth the design, development and history of the Sterling.
We would like to thank Graham over at www.slomocamco.com for the loan of the brilliant slow motion camera which captured this great footage!
The AAI Corporation was founded in 1950, as Aircraft Armaments, Inc., and has long been involved in advanced firearms design, taking part in a number of the US military’s previous small arms programs. Throughout the Cold war AAI was involved in the US Army’s search for a new advanced infantry weapon system. Before we examine the AAI ACR, it is important to understand the context in which it evolved.
The Special Purpose Individual Weapon (SPIW) program, an off-shoot of Project SALVO began in the early 1950s and ran until the late 1960s. During the SPIW program AAI developed a series of designs, including an entire family of weapons, which used flechette technology. These culminated with the XM19 rifle, or SFR – Serial Flechette Rifle. The XM19 represented the pinnacle of over a decade of flechette technology development, however, the end of the US war in Vietnam saw the need for SPIW disappear and the program was wound down.
In the early 1970s SPIW essentially morphed into the Future Rifle Program, but with the end of US involvement in Vietnam, this also proved a failure. During the early 1980s the US Army awarded development contracts to both AAI and Heckler & Koch to develop caseless ammunition and a weapon system capable of firing it. While H&K G11 is no doubt the better known of the two weapons, AAI’s Caseless Weapon, while a move away from flechette technology, was also an interesting design.
Firing a variety of ammunition the AAI design was capable of firing a high cyclic rate 3-round burst at 1600-1800rpm. The ACR program summary report noted that the AAI Caseless project was feasible and only lacked development funding to make it a reality, as the design was much simpler than the G11.
AAI were one of six companies to respond to the ACR program’s Request for Proposals, released in September 1985. AAI’s ACR was an evolution of the earlier SFR/XM19 rifle. The weapon AAI submitted was gas-operated, fed from a 30-round box magazine, and fired a brass cased flechette round in either single shot or a high cyclic rate three round bust – fired at a cyclic rate of ~1800rpm.
AAI’s ACR fired from a closed bolt and used a muzzle device to reduce muzzle climb during burst firing. The 1990 ACR Program Summary report explains how the rifle’s gas system worked:
“…incorporate an ‘entrapped gas’ operating system. Gun gases enter a cylinder, drive a piston to power the system, and prevent any leakage of propellant gases and residues into the other mechanism parts.”
AAI developed a polymer saboted steel 10.2 gr ‘sub-calibre’ flechette which fitted within a standard M855 brass case. As a result the rifle used a proprietary magazine to avoid the accidental chambering of conventional 5.56x45mm rounds. The flechette rounds had a muzzle velocity of 4,600 ft/s with propellant produced by the Olin Corporation.
The rifle was designed to mount a quick detachable 4x optic and also had a white-highlighted shotgun-style rib sight along the barrel to aid snap shooting. The rifle was one of the longest entries with an overall length of 40 inches or 101.6cm. Interestingly, rather than a push-button magazine release, AAI opted for a large paddle release.
AAI’s rifle borrowed some of its external ergonomic characteristics from the M16A2, then in service. With a moulded polymer pistol grip and butt, forming part of the lower receiver, shaped to mimic the M16’s. It also utilised the M16’s sling loops and butt plate.
According to the ACR program summary the AAI entry proved to be a “mature design which performed in a reliable fashion” during the field trials. It was regarded as a weapon with known reliability with a flechette round superior to the Steyr, the other flechette-based entry.
Today, AAI continue to develop both small arms and other defence technologies. Now a part of Textron, they are currently involved in the US Army’s Lightweight Small Arms Technologies (LSAT) program.
Specifications (From 1990 ACR Program Summary):
Length: 40 inches / 101.6cm
Weight: 9.39 lbs / 4.26kg
Sights: Iron or 4x optic
Action: Gas operated
Calibre: 5.56mm brass cased flechette
Feed: 30-round box magazine
You can find out overview article on the ACR program and all of the rifle here.
Advanced Combat Rifle, Program Summary, Vol.1, ARDEC, 1992 (source)
‘Revisiting the SPIW Pt. 1-3’, Small Arms Review, R. Blake Stevens, (123)
The SPIW The Deadliest Weapon that Never Was, R. Blake Stevens & E.C. Ezell (1985)
Our thanks to the collection that holds these wonderful examples of the ACR rifles
The Australian military adopted the F1 submachine gun in 1962, with the first guns reaching troops in April 1963, it replaced the venerable Owen gun. Like the earlier Owen the F1 had a top-mounted magazine – a position that lent itself to prone firing and more comfortable carrying when slung. But it also shared some similarities with the British L2A3 Sterling.
The F1 entered service alongside the Australian L1A1 (self-loading rifle/FN FAL), it shared the rifles butt plate and pistol grip – slightly minimising additional unique parts needed by the submachine gun. Australian Ordnance had begun searching for a replacement for the ageing Owen gun after the Korean War. The Owen had been made quickly and cheaply during the Second World War and while it was well liked by Australian troops it was felt it could be improved upon. Maintenance of the older Owen guns proved difficult as each weapon had been hand fitted to speed up production and some parts proved not to be interchangeable.
A number of designs were developed including one designated the ‘Kokoda’ (presumably after the Kokoda Trail campaign fought by Australian troops in 1942). This design was lighter than the Owen but suffered from overheating problems. A series of designs from the Australian Design Establishment, designated the ‘X’ series, were then developed. These weapons incorporated elements from both the Owen and the British Sterling. Including the Sterling’s perforated barrel jacket and magazine and the Owen’s bolt, magazine orientation and forward pistol grip – a feature many troops with experience with both the Owen and F1 lamented to loss of with the adoption of the F1. The first two ‘X’ series weapons developed into the X3 which in 1962, after successful trials, became the F1.
The F1 used a standard blowback action with a non-reciprocating charging handle. The charging/cocking handle was positioned on the left side of the receiver with its slot protected from the ingress of dirt by a dust cover. The F1 has a two-position fire selector with up for ‘safe’ and down for ‘fire’. The trigger mechanism allowed for firing single shots by pulling the trigger to the half-way point, this allowed the sear to trip into the semi-automatic position (see the diagram below).
Chambered in 9x19mm, the F1 fed from a 34-round curved magazine, although it could use straight, single-feed, Sten or Owen magazines. In the 1960s, in order to achieve commonality with Britain and other Commonwealth nations, that used the Sterling Submachine Gun, the Australian government contacted the Sterling Armaments Company to enquire how much a license to produce Sterling’s magazines would cost, only to be quoted an exorbitant fee. The Australian government were unwilling to pay for the license and produced them anyway. And as Sterling could not afford to take legal action were able to continue to do so – with the understanding they would not sell any commercially. The Australian government would later purchase a number of suppressed Mark 5 Sterling-Patchetts, also adopted by the British army as the L34A1.
The weapon’s ejection port was located on the bottom of the receiver ahead of the trigger guard. A small piece of metal was added in front of the ejection port, as a hand stop, to prevent the operator from inadvertently moving their hand over the port. The F1 had an in-line stock fitting into the rear of the tube receiver. The sights were offset to the right, the rear peep sight folded against the receiver when not in use while the front sight, rather than over the muzzle, projected from the right side of the magazine housing. The F1 could also mount the L1A1 self-loading rifle’s standard L1A2 sword bayonet.
The F1 weighed just over 7lbs (3.2kg), was 28 inches long and had a cyclic rate of approximately 600 rounds per minute. It had a solid butt stock, unlike the Sterling which had a folding stock. The F1 was produced solely by the Lithgow Small Arms Factory with most sources suggesting 25,000 were produced for the Australian military between 1963 and 1973. The Lithgow Small Arms Factory Museum were kind enough to look into the exact number made for us, and reported that there is some uncertainty surrounding the exact number produced with production report totals varying, giving a total of either 21,916 or 24,828.
The F1s saw extensive service in Vietnam and later with Australian peacekeeping troops through to the 1990s. It was issued to rear echelon troops, ACP and aircraft crews and to infantry sections. While the F1 was appreciated for its reliability, for those troops who had experience with the venerable Owen Gun, the F1 lacked a certain something. Colonel Warren Feakes noted that “every time I picked up an F1 I had the feeling that something was missing.” Another Australian veteran, Warrant Officer Kevin Konemann, who served in Vietnam in 1966-67, recalled: “It was awkward to fire from the shoulder and more awkward to fire from the hip” and that “the F1 wasn’t popular. Soldiers found it more difficult to point and bring on target than the OMC [Owen Gun] and firing from the shoulder… was decidedly more difficult without the front hand grip.”
Despite the shortcomings identified by some troops the F1 remained in service alongside the L1A1 self-loading rifle into the early 1990s, when both were phased out of use as the 5.56x45mm F88 (Steyr AUG) was adopted.
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.