I'm a US citizen that has spent a significant amount of time outside of the US. 35 years in the US, and 16 years now in New Zealand. And it's not plainly obvious to me. Bowling for Columbine movie pointed out that Canadians have just as many guns, but much less shootings.

I'm in New Zealand. New Zealand has guns. You need to take a class and be approved by the police who interview you and inspect your gun safe. Pistols are much harder to get. More than 10% of people have a gun license. There is almost no culture of using guns for self-defense against other humans. Farmers consider them necessary tools on the farm, hunters use them to hunt food, and DoC workers use them to cull pests (so do farmers). I also feed my dog about one-third of her diet by shooting rabbits and possum. Recently certain semi-automatic weapons were prohibited, but even before that we didn't have school shootings. Sometimes a family household would be slaughtered by a member of that household. Last night in Auckland seven houses were shot up in gang related violence.