Annual gun deaths peaked in 1993. The following year, Congress adopted an assault-weapons ban that capped magazines at 10 rounds. Since the ban expired in 2004, handguns with 15-round capacity or greater have been used in several mass shootings, including the Virginia Tech massacre (55 victims); the attempted assassination of Representative Gabby Giffords (19 victims); and the 2009 Fort Hood massacre (45 victims). Over the past decade, annual gun deaths have crept gradually upward.
If I am following the logic, the lapse of the assault weapons ban, specifically the lapse of a limitation on magazine capacity, has led to an increase in gun deaths. The link is to a Violence Policy Center study showing that, yes, gun deaths have drifted up and now exceed automobile fatalities in 14 states.
And yes, we have been around this track before. When the topic is gun control as expounded by the gun controllers, "Gun deaths" includes suicides. Well, unless the topic is the intersection of mental health and gun control in which case (remembering that in prog-world the mentally ill are victims of the oppressive white patriarchy) the topic shifts to homicides only.
So the VPC delivers a chart noting roughly 30,000 annual gun deaths, of which about 2/3 are suicide. I admit that there may be a link between suicide and access to guns because a suicidal impulse can be transitory but guns are quick and conclusive [links in this post]. However, I am unaware of any study linking the suicide rate to magazine capacity; if we are having an epidemic of people shooting themselves fifteen times and bleeding out, I've missed it.