Why shouldn't bump stocks be subject to the same regulations as automatic weapons?
I am not saying they couldn't be. (Can't have one made after 1986 unless you are law enforcement or military? --Oh, that won't work.)
First off, the BATF twice okayed them under the Obama administration. So they haven't been.
Second, and here is where the waters get muddy, is defining a "bump stock". Is that
any device which permits a semi-automatic weapon to be fired like a full automatic weapon? Because the finger is an integral part of that, as is a trigger. There are a large number of Machine Gun
parts which are defined as "a machine gun" under BATF rules, and doing something similar with bump stocks could redefine a rubber band. A bootlace. A piece of para cord as such an enhancement device and subject someone to felony charges, imprisonment and fine for a bootlace.
If there is to be such a definition, it must be specific and narrow or it will end up hurting a lot of people who are law abiding folks. For that reason, I am against it.