I think the most un-PC handguns would be the ones you would show people and say that they are the type used in high profile crimes. For example:
"This is the same type of revolver that Sirhan Sirhan killed Robert Kennedy with (would really get older liberals mad since he was a Kennedy who would have been a future prez that would have created Camelot II in their minds)"
This Glock is the same type that the guy in TX killed nearly two dozen people with"
"This is the same make of pistol that one of the kids at Columbine used"
Many of those might not necessarily be scared of an image of a particular handgun, but rather that a specific make was used to commit crimes that horrified them. And of course, the user (the actual perpetrator of the crime) is overshadowed by an tool used. Witness the Time magazine cover in '93 when the cover story was on the Long Island train shooting and the cover caption said 'Colin Fergeson', while the image was the Ruger handgun that he used.