I think our differences is I would like to see us delve deep into society first to find the causes for these mass shootings. Once we know the causes, if eliminating guns with higher capacity magazines helps, then by all means. You want it the other way around. I think these mass killers who kill for killing's sake will find other means. Bombs, arson, chemicals etc. Easy enough.
IfI remember correctly, the NRA has consistently lobbied against any government funding to study the psychological causes of the gun violence issue. NRA and gun violence research