just wondering where do they get this meassurement? was reading an article comparing several cartridges in 6.5 and the 25-06 was one of the cartridges in the article. the article went on to say that a 25-06 wasnt a true 6.5mm? I dont know about their math but where i went to school .257 is 6.5278mm which makes it the only 6.5 in the comparison. Can anyone shine some light on this for me because im confused?