From The Federalist:

Kerry was obviously referring to the AR-15, again conflating the semiautomatic rifle with the military’s M16 and M4 rifles, which are automatic. He also clearly confused magazines with clips.
All the while, though, Kerry confirmed the long-held beliefs that the only thing he and the candidates he supports want to do with firearms are banning, outlawing, restricting, and denying the ability of law-abiding gun owners to buy the firearms they choose. He warned if voters don’t turn out for Biden, those “AR-16s” and “clips” could make a comeback.