We have many instances of homicide rates from low to high, where gun control has been implemented. The homicide rates generally trend up after gun control is institutited, though cause and effect are hard to differenciate. Perhaps Finland or Sweden could be used, but both had low homicide rates to begin with.
You may be on to something, though, when you note that there are no countries with high homicide rates and high legal firearms ownership. The highest homicide rates are uniformly in countries with very strict firearms laws.
But, as I said, it is culture that determines homicide rates, not legal firearms ownership.
Prediction: we cant agree what to do about the problem, so we will end up doing nothing.