I felt that the laws here before 1996 were about right and I do not think that the 1996 laws were a good idea. The 1996 gun buyback involved replacing semi-automatic long guns with ones that weren’t semi-autos. For almost all misuses of guns this makes no difference—you only need one shot to kill or wound someone. It does make a difference in the sort of incident that prompted the buyback—a mass public shooting, but these are really rare. You could save more lives if you spent the $500 million on something else.
You can see a table containing crime figures before and after the laws here. (I also have them in a spreadsheet.) There has been a modest reduction in homicides and with-gun homicides, but it is not statistically significant, so might have been caused by chance.