The story of the Austen submachine gun did not end when the Mk I guns were pulled from combat service in 1944. The manufacturer continued to work on an improved version, which would be ready in 1946, after the end of World War Two. Only 200 were made total, and they were both adopted and declared obsolete in August of 1946.
The changes made to the MkII Austen mostly involved increasing the use of die cast components, which fit the manufacturer’s tooling and experience. The front grip and magazine well casting was enlarged, and the whole rear assembly was made into a second cast part integrating the rear sight, stock mounting and latch, and fire control group. The one significant internal change was to remove the firing pin from the telescoping recoil spring assembly and make it an integral feature of the bolt face.
Many thanks to the Royal Armouries for allowing me to film this very rare artifact! The NFC collection there – perhaps the best military small arms collection in Western Europe – is available by appointment to researchers. However, you can browse the various Armouries collections online.