Uh.. guys, it's like this. The 284 Winchester cartridge uses a .284" bullet just like the 280 Remington and all the other various 7mm's.The 284 Winchester uses a case all it's own,shorter than the 280 but fatter and with nearly identical powder capacity,with a case diameter slightly larger than the .473" base,which is the same base size as the 30-06,280,270 etc.The 308 case with a .284" bullet is known as the 7mm-08.The 264 Winchester is not an '06 case, it is a belted magnum case.It is easiest to describe as a 7mm Remington Magnum necked down to .264",or 6.5mm.But,the 264 came first being introduced by Winchester in 1958 and Remington necked it up to .284" and called it the 7mm Remington Magnum in 1962.Grab a reloading book someday and checkout the descriptions and drawings of various cartridges.Lots to learn there.