Personally, I wouldn't.
These days, I think a Vegas thing is the ticket, but who knows, gotta find a groom first.
Hmmm...
Pro's-
- great excuse for fancy new belt, holster and "barbacue" gun.
- shoot a wedding cake (that is a good idea, only I would make sure to get two cakes and shoot the dry nasty one and eat the tasty one)
- have your FIL carry a slung shotgun. Let the jokes fly (my family would get a kick out of this)
Con's-
- bridal apparel limited, no white silk, satin or lace, no low cut, no long skirt... Basically, no wedding dress, unless you don't mind spending more then you would on a small car and having it get good and grimey within minutes or can find something range appropriate (and safe) that will work (which is gonna be a lot of shopping trips)
- the one I'd honestly worry about arming is the mother of the bride. Especially if she's the managing type who wants a big beautiful wedding for her baby.
Things to question-
- do you really trust *everyone* who's going to the wedding not to have an ND or AD? Seriously, that can ruin a whole day, it's your wedding, and everyone has *that* cousin/uncle/whatever.
- does either family have a history of difficult family get togethers? If Thanksgiving and Christmas are potential drama fests, I'd avoid giving these people guns, gathering them together and expect nothing bad to happen.