((We're talking about some guy that lives in the middle of the woods. He's either crazy or a master at fighting in some way. And niether are something you attack.))
Or, at least, attack without a very good reason. There's a reason Vampires tend to live in cities nowadays- easier to target a random schlub in an alleyway than a guy who's probably a VERY good survivalist and athletic enough to keep off you.
Even if you WOULD eventually kill him, he'd have shotgunned or battered you hard enough that you'd better be hoping that meal's enough to last for, say, the three or so days it takes you to recover from the beating the humie just gave you in his death throes. So you'd have to be pretty desperate to go after a guy like that.
And if you WERE powerful enough to shrug off that, then what the hell are you doing feeding off random humies in a forest, you can probably do it off some asshole in a nightclub and nobody would give a damn due to dominate.
(("Single man living alone in countryside with no family members found missing yesterday."
"OH SHIT JENNY THIS OBVIOUSLY MEANS THAT THINGS LIKE VAMPIRES ARE REAL!11"))
Well, there's enough people who think like this to get SupNat hunters.
Conspiracy theorists aren't the most defended people.
They expect the baddies to hand the good guys the weapons they need to beat them.
Corporations make chemtrails, so we must use vinegar to remove them... which is sold by corporations.
As for shotguns, some supernatural creatures aren't very threatened by that. Actually, I'll list a few (do note that this applies to some kinds, not all).
Vampires are only permanently harmed by oak and running water.
Werewolves are either damaged by silver, or oak and running water (some Vampires can transform into Werewolves).
Kitsune have illusions.
Dragons have scales harder than steel.
Undead creatures can only be killed with either cold iron (iron that's never melted) or something holy (good luck getting that in the middle of nowhere).
Generally you can't trust a shotgun when dealing with supernatural entities.