User blog comment:The Awesome X!/Why don't the monsters use mortal weapons?/@comment-16158784-20130821215800/@comment-5593616-20130822134505

Some demigods do use guns, as shown in The Lost Hero when Annabeth brought out a gun for Piper, but they both agreed it "wasn't her style."

Some do use guns, but most prefer swords/bows/spears.