There is an error in the article. Brazil's homicides are about 15% of those reported in the world, not 50%.
In Brazil any criminal who wants a gun can get one easily. They make it hard for law abiding folks though. Many otherwise honest people just ignore the laws and arm themselves anyway.
Most guns in private hands are Tauruses. Taurus is the only domestic manufacturer and they are cr... not of high quality. ANY US, European or Turkish manufacturer's product will have a definite quality advantage.