From The Federalist:

The key differences between automatic and semiautomatic weapons with bump stocks were largely lost on the justices, especially Ketanji Brown Jackson and Elena Kagan, who repeatedly insisted bump stock-equipped guns can fire up to 800 rounds a second. They, along with the government’s legal team, repeated the lie that semiautomatic rifles with modifiers could fire hundreds of shots (in Kagan’s words, “a torrent of bullets”) each moment. Cargill lawyer Johnathan Mitchell corrected them multiple times.