.303's were found in lots of farm sheds.

These semi wildcats somewhat common.

The .22/303s would have died when the .222 arrived. Edited to add - and .22 Hornet.

The .25/303 with the .243.

The .270/303 with the .270.

As a guess popular period was the 1950s to early 60s.

All of these, the .222,vthe .243 and .270 were very popular. But the .22 RF and 12g accounts for most Aussie firearms.

I seem to remember the .303 was banned from potentially rebelous Aussie civilians hands at some time? Why? And how did that work?