I also have one of the new FN Model 70 Featherweights in .270, and all it needed out of the box was a little trigger adjustment. That was a bit of a PITA, but apart from that, I've been very satisfied with the rifle. Here's how that rifle shoots with ammo it likes:
I am also in the process of reviewing a new (Portugal assembly) Model 70 Ultimate Shadow Hunter SS in 30-06. Best groups from this rifle, with preferred ammo, are one ragged hole.
Unfortunately, it sounds like you got a problem child. If it shoots that poorly and you've eliminated the usual suspect causes, I'd be having a discussion with the factory.