In all honesty if your stock does not have pillars torqueing can be a futile and/or fatal(to stock) mistake. In a wood stock torqueing too much can crush the wood and everytime you do it the screw becomes a "little" too long, in a plastic stock over torqueing runs the risk of cracking the stock.
Do it the old fashion way use a allen wrench short side up and turn in until it is tight. Do the front a little with the butt on a solid suface, then the rear and then back to front.