F1 submachine gun

Lore & Background

The F1 was developed as the X3 and shares many design features with the British Sterling submachine gun. Unlike both the Sterling and its predecessor the Owen, the F1 has a removable wooden butt and pistol grip. A curved, detachable 34-round box magazine is inserted in a magazine housing on top of the barrel, similar to the earlier Owen gun. It used the same magazine as the Sterling. The top-mounted magazine is unobtrusive for carrying and when lying prone; it also benefits from being less likely to jam than a bottom-mounted magazine. The ejection port is directly under the magazine and provides a trap for the unwary user; should the user's hand stray back to the port, the bolt moving forwards will 'bite' the web of the hand. The butt-plate and pistol-grip are identical to those on the L1A1 SLR, as well as the capability of adapting SLR bayonets. However, it was mostly used with a detachable bayonet fitted on the right side of the barrel jacket.

The trigger is a two-stage pull, half back semi auto, pull and hold back gives full auto requiring a safety catch only easily operated by the thumb. There is a small guard fitted forward of the ejection port to protect the forward hand. The left-mounted cocking handle does not have a 'tab' on it. The cocking handle latches into the bolt that allows it to be worked forwards and backwards to clear fouling. The pistol grip with internal parts came from the production line of the SLR L1A1 rifle, at the Lithgow factory. The wooden butt also was from the SLR production line, reducing the amount of tooling. Because of the vertical magazine the sights of the F1 were offset to the right of the weapon requiring a slight head tilt to the right, the rear sight being a roughly triangular asymmetrical metal flap with a round aperture, the front sight being a blade mounted on the right side of the weapon's magazine well.

Although the F1 retained many of the Owen's features it did not continue to have a separate compartment inside the receiver, isolating the small-diameter bolt from its retracting handle, so it was no longer as resistant to jamming if dropped in mud. This is considered a major disadvantage in comparison to the Owen gun it replaced. That being said, the non-reciprocating charging handle blocks off the slot in the side of the receiver to prevent the ingress of dirt.

Reader's Guide

The F1 was produced in numbers of about 25,000 from 1962 to 1973 and served as the standard Australian submachine gun from its introduction in July 1963 until the early 1990s. In Vietnam it was later largely replaced by the US-made M16A1 rifle. The F1 was retired in the early 1990s and replaced by the F88C Austeyr, an Australian-built version of the Steyr AUG rifle. While no longer used by Australia, a shipment of F1s was donated to the Royal Papua New Guinea Constabulary. The weapon was also formerly used by the Royal Malaysian Police, and examples are now on display at the Police Museum. Its design, while robust and simple, never gained popularity with those using it. The F1's top-mounted magazine and shared components with the L1A1 SLR reduced tooling costs, but the loss of the Owen's mud-resistant bolt compartment was a noted drawback. The F1 remains a distinctive example of Australian small arms development, bridging the Owen gun and the later adoption of the bullpup F88C Austeyr.

Did You Know?

• The F1 was designated the X3 while under development.
• The F1 used the same magazine as the British Sterling submachine gun.