That's a big mistake. Concede nothing.
If the left wants to enact gun legislation "that will make a difference", then CCW reciprocity and preventing places of public accommodation from banning firearms is what we should have a pro-gun Congress and President enact.
Criminals disregard "no guns" signs and policies. They prefer them -- no one can shoot back, like Mandalay Bay Hotel Security which has a strict no weapons policy for its members of security.
It wouldn’t be conceding. It would compromising but don’t even worry about it. Bump stocks will end up banned anyways and we won’t get one effing thing out of it as usual.