Gun control does work.
Again, you can't take a law and simply transplant it somewhere else and expect the equivalent outcomes.
Has Australia had a revolutionary war? An armed civil war? Are Australians constitutionally granted the right to bear arms? How many guns were owned before and after the controls?
It's not as simple as just saying "oh, ban them, problem solved". Who collects all the guns for instance?
If gun control works, why were there still 2,519 (adjusted) gun deaths?
You're making an assumption that if you remove a lot of guns from society, that the number of gun deaths is guaranteed to go down and couldn't go up.