it certainly WAS , once, but like most things down under, it slowly caught on an the mid 2000s, the 223 was the go to Roo gun, which is like Every farmer or Farm house would have one.... 80% for the Kangaroos and 20% for the Fox.
quite a few .223 new rifles around, not many new .222s !
RE the mag length, good call, that is something i would have to look at, from memory, not much longer than ye ol 55gr zmax at cannelure!
Good question.