"A year after New Jersey banned the possession of unregistered "assault weapons," a grand total of 18 had been surrendered or confiscated, out of an estimated 100,000 to 300,000 guns covered by the law.California, New York, and Connecticut met with similar success when they required registration of "assault weapons" owned before those states banned them: Only a small minority of the targeted guns, ranging from 2 percent to 15 percent, were actually registered.
Even former Vice President Joe Biden, who joins the other Democratic candidates in supporting a new federal law prohibiting the manufacture and sale of "assault weapons," concedes that the 1994 ban, which expired in 2004, had no impact on the lethal capacity of legal firearms.
In 2017, according to the FBI, all rifles combined—only a subset of which would qualify as "assault weapons"—accounted for just 5 percent of guns used in homicides where the type of firearm was specified, while handguns accounted for 89 percent. Even mass shooters prefer handguns." - Reason.com, Oct. 2019