Gun Control & RKBA

When the makers of the triggers originally ran the specs thru the ATF, the ATF correctly said -- in writing -- the triggers are not machine guns and thus are legal for sale. Years later the ATF changed their mind.

Federal law is quite specific on what a machine gun is per the law written by Congress. (Surprisingly, they got it right.)

The ATF does not have the authority to change/update the law. That is the job of Congress. If Congress wants the triggers to be considered as machine guns, Congress has to update the laws.