AP has an extremely diverse user database.
Some may take offence to an image of piece of steak ( cooked rare ) on a plate because they dislike animal products being used as food.
Others may become upset at an image of motor sport because they feel that all that petroleum product being burned only adds to environmental issues and promotes unsafe driving on the roads.
Yet more members may become upset at image of a brilliant yellow field of canola flowers because they hate the thoughts of genetically modified food sources.
Can't please everyone all the time but in general from what I have seen on AP there has been no howling backlash against images featuring firearms or ammunition, quite the opposite in fact where some extremely well done shots have been lauded very positively.