The majority of gun deaths in America are suicides. Suicides are also the type of death most easily deterred by restricting access to guns: Israel has had success curbing military suicides by not letting soldiers access guns on their downtime and Australia saw a sharp drop in suicide rates when it instituted its gun buyback program, with states with more aggressive buyback programs seeing a bigger drop faster. These are not the only studies that indicate this, and the result has "microfoundations" in psychological literature: restricting the means by which someone can kill themselves is a key step in treating patients, having a gun in the home is a risk factor for suicide, etc.
Meanwhile, mass shooting deaths are a fraction of a fraction of America's 31,000 plus annual gun deaths, and the relationship between gun control and crime is harder to suss out.
So gun control is about suicides. This is good, because it gets us to a core reason we might need state paternalism -- to protect the mentally ill from their crazy decisions. It has the added benefit of being less condescending to gun owners: "we know you are responsible, we know you can handle your weapon safely, but we are worried that some depressed member of your household is going to use that gun to off themselves when they aren't thinking straight."
And it gets the numbers into a world where severely restricting gun rights makes sense: the economic impact of the firearms industry was about 31 billion dollars last year (by their trade group's estimates), meaning, if we value lives at about $7,000,000 (a standard figure in public policy planning, I think), we only need to save just under 4,500 lives a year to make the complete death of the gun sales industry worthwhile. Not only do I think that is a realistic figure (there are 17,000 plus firearm suicides a year; deterring just a quarter of them from killing themselves would get us there), I think we can stop short of completely ruining all the utility people get out of gun ownership and completely bankrupting the industry (licensing guns to people when need can be shown (security guards, cops, etc), allowing rentals for firing ranges and hunting, perhaps still allowing a tightly regulated collecting hobby, etc).
So passing a restriction on big magazines or assault rifles to prevent mass shootings might be a marginally good idea, but it is going after a really small problem. The problem is suicide. The solution is heavy gun restriction.
If you think that people have an individual right to bear arms in the constitution, the solution is repeal of that right and heavy gun restriction.