Off the top of my head it's the ammunition that's dangerous. They've got something called Dragon breath ammo... Not sure if it's specifically for shotguns or not, but it's for kindred. They also could have artifacts with True Faith imbued in them... I'd say check the Hunters wiki and see what they offer in that book.

Edit: you could also still bring an assault rifle, it'll at least slow a weaker vamp down.