[T]he evidence on the effects of universal background checks and assault weapons bans is pretty weak. Several studies in recent years have found that universal background checks, at least on their own, don’t seem to have a big effect on gun deaths. Similarly, the research on assault weapons bans, including the national ban that Biden helped pass in 1994, found they have little effect on gun violence, largely because the vast majority of such violence is committed with handguns. …
One way to explain these findings is that the reach of universal background checks and assault weapons bans is too small. The US already has background checks for most legal gun purchases, and all universal background checks would do is cover the minority of gun purchases not detected in the existing system. An assault weapons ban would cover a minority of guns used in crimes and would probably have loopholes that miss segments of that minority.
— German Lopez in The case for requiring gun licenses
