I know my vampires Buffy, Dracula, Thirty Days of Night, Salem's lot, Blade, Van Helsing, Vampire the Masquerade and Requiem, as well as dozens of other mythological appearances of vampires or vampire like creatures (asanbosam, mandurango, ect.) hell i've even read twilight (Not that those are really vampires), Hence my characters use of a shotgun. Get close enough and 12 guage will take a head right off. However, and this purely because Eddie pointed out he's drawing on Bram stoker's Dracula, wood to the heart typically works. Which you really can't fire from a gun XD 
The silver was reference to werewolves typical weakness but we could go back and forth on werewolves for days too. 

But in conclusion: Yes I absolutely agree stylistically I'd have gone with the crossbow too.