Quick question about the case way; you ignore all survivors and are killing zombies with the SUV in between case files/zombrex for Katey, right?
Also, is it recommended swapping to the bike after Leon appears? (And after killing him, of course.) I imagine it'd be a lot quicker getting the achievement with Gas Zombies about, but I was afraid to try... I would hate to realise I've come up short after attaining so many kills! :P
Depending on the response, I may need some magazines dropped. =)