Do you really mean bullets, projectiles for reloading? If so, handlerer2 is right.
I ask because there are a lot of people who call cartridges "bullets."
If the OP is one of them, then the .280 Remington cartridge is NOT the same as a 7mm Mauser or a 7mm Remington Magnum, the most common (but not the only) 7mms to be found.