The ballistics of the .260 Remington are basically similar to a cartridge developed in what year?
.260 Remington: The .260 Remington (also known as 6.5-08 A-Square) cartridge was introduced by Remington in 1997. 6.5×55mm: The 6.5×55mm (designated as the 6.5×55 Swedish by the SAAMI and 6,5 × 55 SE by the C.I.P.) is a first-generation smokeless powder rimless bottlenecked rifle cartridge.
i don't know