The japanese model is exactly the same as in NZ. We have significant number of gun deaths per year but not huge percentage wise.
I think Japanese culture and comparative wealth are big reason gun crime there is low.
Brazil is hard-core gangland in some areas so they prob keep every gun on the blackmarket they can get away with, just to stay on level with all the other gangs.
My point would be that gun control is important element in the equation [for reducing gun crime], but isn't the only part of the equation. You have to look at it and treat it as a valid component, but without the social environment being considered, it won't solve all your probs.
Licensing of owners, and only being able to sell to license holders made a big difference here. But to allay enthusiasts, even with license I can go and shoot assault rifle and pistols till i run out of money. None of that stuff is banned, just licensed via tiers. I've never considered it draconian. It's just like getting a car license, but with a background check for crazy and criminal history. Pistol license is like getting big rig license. Less people have it but it's not hard to get.
The govt doesn't know how many weapons a licensee has, just that the licensee is vetted.