Given that the first sentence mentioned developed nations I figured it was clear I meant any developed nation. Furthermore, regulates guns generally means actually regulates guns and not "has laws for regulating guns." The two are not the same except in countries that have stable governments, enough money to pay for law enforcement and low amounts of corruption. Unless you actually believe the state of the US government and economy is akin to that of a country like Brazil?

Brazil has the world's 9th largest GDP. Does this look like an undeveloped country:

https://en.wikipedia.org/wiki/S%C3%A3o_Paulo

Depends if you live in this part of Sao Paulo or not:

https://en.wikipedia.org/wiki/Favela

Brazil is around the 80th in terms of per capita GDP which is a much saner metric for the wealth of a country in terms of social issues.