I have only fooled with one plastic stock, they are to me, butt ugly! But I got one as a gift years ago from a girl friend. Had to let her go for getting me something like that! The rifle, Rem 700 ADL, did not shoot well at all, bedding was worst I'd ever seen. once I got it cleaned out to where you could get the barrel action out without pounding on the barrel in front of the stock, I re-bedded the action area tight but still able to lift it out. I've read about the horror's of plastic stocks bending around, think that's the right word, when shooting and read about epoxying a push rod in there to stiffen the barrel channel. I didn't have a push rod so I took another route. From the front of the action forward I floated the barrel a good bit. Trying to recall, think I could slide four pieces of typing paper between the barrel and stock all the way to the action. My thought was to remove enough stock that it couldn't bend far enough to effect the accuracy. Seem's to have worked well. Rifle went from firing pattern's to a 1/2" rifle. Have since replaced that thing with a wood stock. The old girl friend now lives in southern Texas, good three day drive from here, fairly safe distance!
Something to note, if you go ahead and float the barrel like that, you can always put back material using epoxy and tighten it up some. My favorite is liquid steel!