In total 19,914 Austens were produced during the war by Diecasters Ltd of Melbourne and W. T. Carmichael Ltd of Sydney.

[8] The barrel, body (receiver) and trigger mechanism of the Mark II Sten were copied, while the folding stock and bolt, with separate firing pin and telescopic cover over the return spring, were copied from the German MP40.

The weapon had a selective-fire feature permitting the operator to fire single shots or fully automatic at 500 rounds per minute.

[9] A second version, the Mark II Austen, was developed during 1942 and 200 were manufactured by the end of the year for trials.

[11] This model made even more extensive use of diecasting; the large grip assemblies at both the front and back of the gun were produced in this way.