I think so, i used to have one that was in a wooden chest, the handle was on the underside of the barrel. Had a piece of paper and a picture with it saying it came from HMAS Australia, bit hard to believe as the ship was scuttled 20 odd years before the gun was made!
Maybe from the second HMAS AUSTRALIA? 8 inch cruiser in service from about 1927 to late 1940's.