I have a remington model 7 in factory plastic stock. The rifle produces 2.5-3 moa groups at best with everything I fed it, including handloads.I tried bedding the stock with acraglas, adding pillars, etc., but it still won't shoot. Once I put it in a b&c stock with aluminum v block, it started to produce 1.5 groups with factory ammo.
I used to think acraglas could fix any bad plastic stock, but my experience told me otherwise. Being said, I've seen tikka shooting very respectable groups with the factory plastic stock, so if your rifle is already shooting well, the gain might be limited.