The plurality, if not majority, of shooting is where a pistol is used and has become a norm in certain cultures. Those countries don't have those cultural issues. A part that makes America such a great place (diversity) is also part that holds a truth there is a deep cultural issue that uses handguns for terrible ends.
Secondly, you could say that not all liberal policy is directly, or tangentially, related to issue at hand. Fiduciary and fiscal policy, liberal vs conservative, may not tie in as a tenet that solves anything here. I think it's too high level to say "country x = more liberal = less violent."
Australia and Sweden have significant rape issues. We'd both say we're not okay with rape, mass shootings, burglary etc. Given the thread is gun control, it's the proper focus to talk about guns. But looking at related issues (violent crimes, mental health, human condition, policy) is valuable.
Net: I believe there is a culture issue in America where gun violence animates from. I believe it makes sense that, the country with the most volume of guns, and culture issues other countries might not contend with, has poor statistics here. However, violent crimes and humanity depravity exist everywhere whether a gun ever existed or not.