They can't be able to fire anything, a non-moving trigger is nice but not usually required, and I'm pretty sure they need an orange tip if they resemble a real-world gun. This is going mostly off of what my friends have experienced, most cons, and the weapons check rules, as I haven't (yet) used a gun prop at AN.
Originally Posted by Moofingham
There is a vibe here that says "We're in this together! Through thick and thin fabric! Through cold water washes and burning hot irons! Though we might super glue ourselves to our projects, cut holes/gashes/oh-god-mom's-gonna-kill-me into the dining room table, we will stand strong together. Unless there is a 75% off sale at the Fabric store. Then you're on your own. And get the hell out of my way." <3