A sear is a standard part, and legal on its own. A specific design, an “auto sear”, prevents the weapon from locking back up in battery after the slide/bolt ret

A sear is a standard part, and legal on its own. A specific design, an “auto sear”, prevents the weapon from locking back up in battery after the slide/bolt returns. That’s effectively a “machine gun” and unlicensed (technically, untaxed) ones are a felony to possess since 1981. The anonymous creator is an idiot for making them, much less using them in a publicity stunt.