some interesting numbers:
2/3 of firearm-related deaths in US are suicides, very low in other countries – but total suicide rates are same as in Canada, UK, France …. So, firearms here is just a tool … slowly increasing thru Obama years though
homicide rates in US are 3x times more than in West Europe. It increased 2x from 1960 to 1975, stayed flat till 1994 and then starting decreasing 2.5x till 2010 (welfare reform, good economy?), with a slight bump in 2014-16 and then back, 2019 (latest I see) is the lowest point. So, it is a problem, but not really an increasing one.
Rates very significantly by state: NE and NW are mostly 2-3 per 100K per year, south and MidWest is 6-8. New Hampshire is lowest 0.9 as in Europe. Some looked at gun-friendly states, they include both highest (MS) and lowest (NH) by murder rate (of course, which causes what is not clear). Strictest states have mostly low murder rate (NY,NJ, but also some higher than average (MD, DE,IL)
So, it is possible that strict laws prevent worst murder rates, but it is quite possible to have low murder rate while being gun-friendly (