Every time we write about the ATF’s bump stock ban, plenty of commenters write that they can’t understand why anyone would want one. They opine that no one will miss them now that they’re officially verboten. That’s completely missing the issue at stake and why the ban is so dangerous.
Bump stocks facilitate a fast rifle shooting technique in which the shooter pushes the gun forward so that the trigger is activated by a stationary finger, at which point recoil energy causes the gun to slide backward, resetting the trigger. Contradicting what the ATF had consistently told bump stock manufacturers and members of Congress, the Trump administration declared that rifles equipped with these accessories are illegal machine guns.
As Damien Guedes and other bump stock owners point out in their challenge to the ban, that conclusion is plainly at odds with the legal definition of a machine gun, which requires that the weapon fire “automatically” and “more than one shot” by “a single function of the trigger.” Bump firing is not automatic, since it requires the shooter’s active intervention, and it entails resetting the trigger after each round, as with any semi-automatic weapon.
The question raised by Guedes’ lawsuit is not whether banning bump stocks is a good idea. The question is whether bump stocks are already banned.
By pretending they are, Trump is usurping congressional authority and criminalizing conduct that everyone thought was legal until he arbitrarily decreed that it wasn’t. Like the cop who decided that Joseph Cracco’s pocket tool was a forbidden weapon, the president is making up the law on the fly.
– Jacob Sullum in Gravity Knives, Bump Stocks, and Lawless Law Enforcement