One of my brutal, mainstream-ish vampire stories, Night Burn, was republished on the Every Night Erotica site. (It was originally published, in a less developed and shorter form, on the Erotica Readers & Writers Association site in November 2001.)
This 1,984-word story has a brief spot of sex, but it could easily be republished, as is, in any mainstream horror magazine.
Night Burn is not recommended for Stephenie Meyer/Twilight fans. (You were warned, gay boys and sparkly-eyed girls!)