Ultimax 100 Light Machine Gun

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.

Ultimax MKII
A MkII Ultimax which featured a fixed barrel (source)

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.

Diagram from an early marketing brochure showing the MkII and MkIII models of the Ultimax (source)

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.

Ultimax 100 Sales Brochure cover
Cover of Chartered Industries sales brochure for the Ultimax 100, featuring a MkIII, note the bayonet lug (source)

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.

Technical Specifications (from 1982 Sales Brochure):

Length: 103cm (40 in)
Weight (unloaded): 4.7kg (10.4 lbs)
Barrel Length: 50.8cm (20.0 in)
Action: Gas operated
Calibre: 5.56x45mm
Feed: 100-round drum or 30-round STANAG magazines
Cyclic Rate: ~400-600 rpm


The Interview: L. James Sullivan, Part II, 28th February 2007, Small Arms Review, (source)

1982 Ultimax 100 Sales Brochure, Chartered Industries of Singapore, (source)

The Past is Another Country: Ultimax 100, WeaponsMan, (source)

Military Small Arms of the 20th Century, I. V. Hogg, (1985)

F1 Submachine Gun

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.

Men of the 7th Battalion, The Royal Australian Regiment demonstrate the F1 to the Australian Army Minister, Malcolm Fraser, in Vietnam in 1967 (Australian War Memorial)

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.

F1 SMG (Matthew Moss)
Left side view of an Australian F1 submachine gun, from the 1970 production run (Matthew Moss)

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.

8RAR with F1 SMG (AWM)
Member of 8th Royal Australian Regiment stood too with his F1 SMG (Australian War Memorial)

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).

Semi-Auto sear position in F1 SMG
Diagram from Australian Army Parts List showing how the F1’s semi-automatic mode works (source)

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.

Australian Sailors with F1 SMG
Australian sailors aboard the destroyer HMAS Duchess wait to take part in a live firing exercise with their unloaded F1 submachine guns, c.1969. (Australian War Memorial)

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.

Technical Specifications:

Length: 28 inches (71cm)
Weight (unloaded): 7lbs (3.2kg)
Barrel Length: 8.35 inches (19.8cm)
Action: Blowback
Calibre: 9x19mm
Feed: 34 round box magazine
Cyclic Rate: ~600 rpm



1966 Infantry Training Pamphlet, Platoon Weapons, Sub-machine Gun 9mm, F1, Australian Army, (source)

Repair Parts Scale, 9mm, F1 SMG, Australian Army, (source)

Vietnam ANZACs Australian & New Zealand Troops in Vietnam 1962-1972, K. Lyles (2004)

Military Small Arms of the 20th Century, I. Hogg & J. Weeks (1985)

‘Another Australian Native: The 9mm F1 Submachine Gun’, Arms & Militaria Collector No.21, pp. 53-56, I. Skennerton, (source)

Modern Small Arms, F. Myatt (1979)

The Owen Gun, W. Wardman, (1991)

F1 Sub-machine Carbine, Lithgow Museum, (source)

Please do not reproduce photographs taken by Matthew Moss without permission or credit. ©The Armourer’s Bench 2018.

TAB: Recommended Reading – The ArmaLite AR-10 by Joseph Putnam Evans

This is the first instalment of what will hopefully become a regular feature where we discuss some of the books we use when researching the guns we feature in our videos. We’ll give an overview of what the books cover, how they approach subjects and how good a resource they are.

With Vic’s recent special episode on the AR-10, I’ve been using Joseph Putnam Evans’ book ‘The ArmaLite AR-10: The World’s Best Battle Rifle‘ to help write the accompanying blog posts. While not without its flaws Evans’ book is without doubt the best published source on the AR-10 currently available.


For many years the published material on the AR-10 was confined to both contemporary gun magazine articles on the ‘new’ rifle and a handful of retrospective articles published later. Very little was written about their surprisingly extensive combat use or even the nuances of the design changes. Even the Black Rifle books, also published by Collector Grade, lacked the context of where the AR-15 evolved from. ArmaLite AR-10 is well worth reading, and a great base for further research.

Special Episode: The ArmaLite AR-10 (Pt.2)

If you missed the first part of our special episode on the AR-10 you can find it here!

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.

Photograph from the Bundeswehr rifle trials of a German soldier firing an AR-10/G4 in 1957 (source)

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).

Soldier firing an AR-10 during the Dutch Army trials (source)

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.

Caçadores Paraquedista with an AR-10 (source)

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.

Portuguese contract AR-10 (source)

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 the next part of the series Vic will examine several examples of the belt-fed AR-10. If you missed the first part of the series, which featured the early history of the ArmaLite AR-10 and a very rare original promotional film featuring Eugene Stoner himself, you can find that here!


The Armalite AR-10: World’s Finest Battle Rifle, J. Putnam Evans (2016)

Hybrid Sten


During our first research trip last spring I had the opportunity to examine an unusual ‘hybrid’ Sten submachine gun. The weapon combined a MkII Sten’s receiver with a MkIII’s magazine housing. Added to this was a proprietary folding stock and a new fire control group and pistol grip.

Very little is known about the hybrid Sten with Peter Laidler’s book The Sten Machine Carbine mentioning it and the later Osprey book by Leroy Thompson sharing a photograph and brief caption which calls it an “experimental version of the Mk III.” It is also unclear exactly when it was built.

Below are some photographs I took of the Sten, lets look at some of the interesting features of the Hybrid Sten.

left side of the Sten with the stock folded flush under the receiver (Matthew Moss)

No production Variant of the Sten was fitted with an under-folding stock, the Australian Austen, however, directly copied the MP38/40. The entire weapon is covered by a layer of textured, crackle paint finish, this was commonly used on commercial Sterling Mk4 submachine guns. The weapon has a short, 3.5 inch, perforated fore-end welded onto the front of the tube receiver that appears to be from a Lanchester.

Rear right of the weapon close up of its pistol grip, stock and trigger housing (Matthew Moss)

The under folding stock is rudimentary but effective, the butt plate swivels free but the lock up is quite secure. It uses the receiver main spring-loaded return-spring cap. The folding stock attaches to the pistol grip assembly (which can be seen detached below).

The proprietary rectangular trigger group housing brazed onto the tub receiver is unlike any other Sten and lacks a fire-selector.

Left side of the Sten with its pistol grip and stock assembly detached (Matthew Moss)

The pistol grip itself is made from paxoline, a form of early resin plastic. The shape shape of the pistol grip does not resemble any production or prototype Sten grip. A simple hand-stop, made from a bent piece of sheet metal, has also been added in front of the weapon’s ejection port to prevent the user’s hand moving back and fingers being caught if gripped by the forend.

Right side of the Sten with its stock unfolded (Matthew Moss)

While the origins of the hybrid Sten remain unclear I don’t believe it was an officially made prototype. While impressive it is relatively crudely assembled and does not match the Sten prototypes made by Enfield, such as the VI. Intriguingly, the magazine housing of the weapon has been stamped ‘PILOT’ below the usual ‘STEN MkIII’ stamp. I suspect that the weapon may have been put together by a unit armourer, perhaps authorised by a superior officer to suggest improvements or as an unofficial project gun.

UPDATE:  Their is some evidence emerging that this Hybrid Sten may be related to the T42 Sten prototype, part of the Sten MkIV development program. Where this hybrid fits into the story is not yet clear but the similarities are striking, when we have more information we will revisit this weapon.

Technical Specifications:

Length (with stock folded): approx. 40cm (30in)
Weight: approx. 3kg (7lb)
Barrel Length: 16cm (6.5in)
Action: Blowback
Calibre: 9x19mm
Feed: 32 round box magazine
Cyclic Rate: approx. 500 rpm


The Sten Machine Carbine, P. Laidler (2000)

The Sten Gun, L. Thompson (2012)

Please do not reproduce photographs taken by Matthew Moss without permission or credit. ©The Armourer’s Bench 2018.

1958 ArmaLite AR-10 Promotional Film

In the first part of Vic’s special episode on the AR-10 we brought you a remastered version of the fascinating 1958 ArmaLite/Fairchild promotional sales film made for ArmaLite salesmen, like Sam Cummings and Jacques Michault, to show to prospective buyers of the new rifle. Back in the 1990s Vic was lucky enough to scan Michault’s copy the film and has recently remastered with better image quality.

Below you can find the video, time stamped to begin at the promotional film (although I highly recommend you watch the entire video for Vic’s introduction to the early history of the AR-10).

Lets break the video down, with the help of some screen captures. The film opens with a rifleman emerging from the sea, firing as he advances. The film then explains Fairchild’s background and beings to explain the features of the rifle.

Fairchild Armalite AR10 Promo (16).Movie_Snapshot
Arrows point out some of the AR-10s controls
Fairchild Armalite AR10 Promo (17).Movie_Snapshot
A close up of the rifle’s bolt and carrier
Fairchild Armalite AR10 Promo (20).Movie_Snapshot
A set of scales is used to demonstrate how the AR-10 (plus 50 rounds) is equal to an M1 Garand

The film then shows several shots of the rifle’s lower receiver being milled.

Fairchild Armalite AR10 Promo (4).Movie_Snapshot
The milling of the rifle’s aluminium-alloy forged receiver

None other than the rifle’s designer himself, Eugene Stoner, then takes an AR-10 from a wall display and proceeds to completely disassemble it.

Fairchild Armalite AR10 Promo (6).Movie_Snapshot
Stoner standing in front of a display board holding three AR-10 prototypes and AR-5s and an AR-7 survival rifle

Stoner completely strips the rifle, its muzzle device and its magazine before Charles Dorchester, ArmaLite’s production manager, demonstrating the rifle’s operation and subjects it to sub-zero temperatures and once again firing the rifle.


The film then shows the rifle being used in a variety of roles:

Fairchild Armalite AR10 Promo (26).Movie_Snapshot
AR-10 being fired with a scope mounted to the carrying handle
Fairchild Armalite AR10 Promo (27).Movie_Snapshot
The AR-10 being fired from a bi-pod in the light support role, feeding from 20-round magazines, the AR-10 LMG could easily be switched between magazine and belt feeding by removing the belt feed assembly
Fairchild Armalite AR10 Promo (28).Movie_Snapshot
An ENERGA rifle grenade being fired from the AR-10, the US Army had adopted the ENERGA as the M28 rifle grenade in 1950.

Stoner then covers the rifle with sand before running five magazines through the rifle in quick succession to demonstrate reliability:


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The rifle is then submerged in mud (with its dust cover closed) and demonstrated again.

Fairchild Armalite AR10 Promo (32).Movie_Snapshot
AR-10 covered in mud

The film then shows how simple field stripping and cleaning is before Stoner demonstrates the belt-fed variant of the rifle:

Fairchild Armalite AR10 Promo (41).Movie_Snapshot
A rifleman demonstrates the AR-10 in its belt-fed configuration, changing position several times before switching to feeding from magazines. Note also the ‘backpack’ belt box and controlled chute/feedway
Fairchild Armalite AR10 Promo (40).Movie_Snapshot
Stoner firing the belt-fed AR-10
Fairchild Armalite AR10 Promo (39).Movie_Snapshot
Stoner with a happy grin on his face before opening up with the AR-10,
Fairchild Armalite AR10 Promo (15).Movie_Snapshot
Note the bolt link port in the lower receiver

Don’t forget to check out the full episode and the accompanying blog here!