Does your gun's buttstock slide on easily, so that the stock screw inserts freely? Or do you have to force the stock to jam up against the receiver before you insert the screw? The blind hole in my gun's stock... the one that houses the bolt-return spring... is drilled a little short, so that the spring plug bottoms out before the stock is fully on. It's hard to believe this slipped out of the factory unless it's supposed to fit this way. But if it is, why?