Abstract: A rotary cooker and/or sterilizer is provided with a novel rail design to facilitate processing of chamfered, stackable cans and which prevents damage to the protective coating of chamfered, stackable cans which occurs in prior art rotary cookers. A split rail is provided having an inclined track for carrying and guiding one end of chamfered, stackable cans and a flat track for carrying and guiding the other ends of the cans so that the side wall of each can does not contact the rail and is not subjected to the abrasion of the side wall of the can otherwise caused by prior art flat rails used to carry and guide both ends of the cans. The rail design includes flanges for limiting side-to-side motion of the cans as well as rail segments which are placed in the rotary cooker wherein each rail segment supports and guides the top ends of cans in one row of cans and the bottom ends of cans moving in an adjacent row of cans.