Bullet shell id

Found a bullet shell metal detecting at a gun range operational in the 1950s and 60s in South Australia.
The headstamp says MF and 018 or 310 (not sure which number it is) in the photo below I have placed a .22 for comparison. The measurement is 9mm by 28mm

.310 Cadet Rifle

310%20Cadet%20Australian%20(MG%20%26%20MF)

310%20Cadet%20Australian%20-%20MG%20HS

310%20Cadet%20Australian%20-%20MF%20HS

Sorry for duplicity…I have uploaded pictures prior reading another thread.

WWII Australian production FMJ
for use by Volunteer Defence Force
In case of Japanese Invasion.
MF Footscray No. 1 SAA FACTORY
MG Footscray No. 2 SAA FACTORY
Only made during 1942-4, in FMJ.
Lead bulleted cartridges are from
Early 1900s to WWII.( mostly imported, although Footscray did make small lots before WWI.).

Doc AV