26" barrels

[scalerman]

Just a quick question for you guys. How much difference in muzzle velocity is there between the 7MM Mag and the .280 Remington when both are fired out of a 26" barrel? I notice that in most reloading manuals that a 7MM test barrel is 26" long and the 280 is 22" long. Does any body have any numbers on this, or perhaps could direct me to someone who does.