Originally Posted By slappomatt:
sounds like your stock is a mil spec size. shouldnt matter that the back is slanted.
Some mil tubes have a slanted back and some commercial tubes have a flat back- it's just not the norm. Regardless of how it was marketed, if your tube measures around. 1.150" in diameter and the width of the lower rail is between 0.485-0.495" then a Mil-spec ACS/CTR/MOE stock would be the proper choice.