Its a question of Semantics. No Bump stocks and silencers aren’t guns and so in a literal sense the statement that “Trump grabbed more guns” is incorrect. On the other hand, the bump stock and silencer ban, was one of the few times where something that was legally owned suddenly became illegal to own. Even the notorious assault weapons ban had a grand father clause. So if we consider “gun grabber” in the more figurative sense of someone who is going to take things away from you, then more of that happened under the Trump administration than under previous administrations.
You can argue back and forth about which interpretation is the “correct” one, but in the end its all just boils down to a matter of opinion, or at best supports an accusation of sloppy use of language. Outside of winning rhetorical points it doesn’t really have any bearing on the underlying debate. Far more important is the extent to which the bump stock ban that happened under the Trump administration supports MartinLane’s larger statement