From Washington Post:

My proposal is simply that we revert to the gun laws that prevailed in the United States around 1960. From a public-safety standpoint, that was far from a perfect world. The cheap revolvers called “Saturday night specials” ruled the night in many cities. Loopholes as to the sale and registration of long arms allowed the importation of the mail-order rifle that Lee Harvey Oswald used to kill President John F. Kennedy in 1963.