Knee jerk reaction maybe, but it would seem the intent must be to group all firearms together thinking it will make the words “gun” or “rifle” themselves inflammatory.
200 years ago, a “gun” was a smoothbore (like a shotgun), a “rifle” was a long barreled shoulder arm, and a handgun was a “pistol.” Terms have changed. Even during the Old West period from 1866 to 1890, most called their revolvers “pistols.”
Bingo.