A rifle stock assembly adapted to receive and support a bolt action rifle barreled receiver is disclosed. The assembly includes a rifle stock/chassis having an elongated recess and a cage removably fastened to the chassis in the recess to receive a bolt action rifle receiver therein. The assembly may also have a pair of magazine collets fastened to the bottom of the forward portion of the chassis defining a magazine well beneath the cage. Cages having different internal surface shapes may be utilized to accommodate different barreled receivers in the same rifle stock/chassis. Different magazine collets may also be utilized to accommodate different caliber magazines used with the different barreled receivers.