Batman Grapnel Gun - Bringing to Conventions?

So, I plan on going to Orlando Megacon next month and I know a lot of weapon/prop rules say you can't have something that fires a projectile. I have the Arkham grapnel gun that has the firing grapnel hook on the end. Now, the hook is attached with string, and only goes out a few feet. I am wondering if anyone else has had experience bringing something like that to a con? Thanks!

You are better off just not bringing it, con rules about cosplay props have gotten way too strict. better to bring a static one out of foam for pictures, also if you loose a foam you will not feel to bad about it..