Hope the contacts fit!!
Anyways, last time I went, they only checked the bag to see if I have the costume (since it was the cosplayer enterance), but they didn't seem to mind the weapon (sword) that I brought.
I only brought guns around for photoshoots (there's this big public monthly one that I talked about somewhere I think;; ), so I'm not sure what's the policy for them around the con.
I saw a Black Rock Shooter with a giant gun if that counts -_-
And a One Piece Strong World somebody. Can't remember the character...
But both of those were giant props rather than a realistic one lol