Thread: Having that 'best deer hunting cal' argument with a mate. 6.5x55 vs .270win vs 308

Originally Posted by Shearer

Not sure where you got your figures from but I would be very surprised if a .277 cal projectile leaving the muzzle 300fps faster that a 6.5mm projectile (give the same type of projectile) would have 78ftlbs less energy, even 30m father out. You have to compare apples with apples which I don't think is the case.
There is also a big difference between 390m and 510m.

In the figures given, both the 6.5 and the 7mm projectile are both 140gr. Since the 6.5 projectile is thinner, it must be longer to have the same mass. Longer generally means higher BC, and therefore is more aerodynamic, slows down less over distance, and retains more energy than a shorter higher cal projectile of the same mass. Seems plausible to me.