Sorta, but not all together. The original 40x used a 722 style bolt handle and trigger assembly, and the stamped 722 trigger guard &floorplate. The 40XB uses the 700 style bolt handle, trigger assembly and ADL style trigger guard. The difference is the bolt handle cut and safety clearance and the trigger guard inlet. The difference in a 40XB rimfire to centerfire stock is that the rimfire stock has a small pocket cut in the center of the bedding area for clearance for the screw that holds the cartridge guide.