The 260 Remington first appeared around 1996. A-Square submitted drawings to SAAMI and named the caliber 6.5-08 A-Square. Many months later, Remington submitted a memo to SAAMI wherein it mentioned that it intended to eventually standardize a 6.5 mm version of the 308 Winchester as the 260 Remington. SAAMI subsequently chose to name it 260 Remington, but it should maybe more correctly be called 6.5-09 A-Square. The 260 Remington has a very good reputation as a long range target cartridge and is also often seen as a chambering in light rifles. Hunting load ballistics is somewhere between 243 Winchester and 7mm-08 Remington. 

This text is based on information from “Cartridges of the World”, Hodgdon reloading manual, the cartridge designer and/or own resources.