[Uman]

Basic military small arms design considerations point to the .260 Remington as the better military cartridge. The reason is it is just a necked down version of the .308 WIN. This cartridge has more of a body taper from the head to the shoulder to facilitate extraction in a dirty chamber. A straight walled case will have more friction on it until the shoulder clears the rear of the chamber. Plus this taper facilitates the feeding from a box magazine better. Think of a triangle vs a rectangle, picture both of them being puled out of a matching slot, the triangle becomes loose after a small movement, not so with the rectangle. Just basic military small arms design that all 18"Bs should know.