I typically hear of the silver bullet being the gold standard (so to speak) weapon for killing a werewolf and rarely hear of other weapons successfully doing the job. Even Wikipedia's article on silver bullets states:
(it) is often the only weapon that is effective against a werewolf
Is the fact that it is a bullet important in some way?
Is there some mythological context to suggest that the velocity is essential, or would any silver weapon (such as a sword) do the job?