This is true, but I think there are two factors which qualify this argument:

1) leverage / scale (a person with a gun can kill more people in a shorter space of time) 2) it is contended whether or not this is killing someone, whereas noone (probably, almost) contends whether a school shooting is killing anyone

Even with large numbers of people thinking abortion is murder, this is overwhelmed by the number of people thinking that shooting someone is murder. Since murder is considered (probably) by a similarly large majority, and a gun can create more murder than an abortion, you could make a far stronger public interest case for CC companies to apply pressure to one rather than the other.