What non-sense.
StrayDog,
First of all, specific bullets are what make all the difference and there are many more bullets with superior aerodynamic designs in 6.5mm than in 0.277". The AB is far from the best-suited bullet to LR shooting, but even if we limit the discussion to the two bullets you mentioned, Nosler's BC values are questionable at best. Bryan Litz estimates the BC of the .277 140 AB to be the same as the 140 BT, which has a G7 BC of 0.227, and he estimates the 6.5mm 140 AB to have a G7 BC of 0.249. Secondly, you're comparing a SA cartridge to a LA cartridge, which isn't exactly apples to apples. Despite all that, using Hodgdon's data for both the 6.5 Creedmoor and the .270 Win, and looking between 0-1000 meters under SAC, we have the following:
6.5 Creedmoor
24" barrel
140gr
2806 fps max
.270 Win
24"
140gr
3033 fps max
Using those numbers, the .277" 140 AB shoots flatter at all ranges of interest, and the two bullets have essentially the same wind drift out to about 700 meters, after which the 6.5mm 140 AB drifts less and less relative to the .277" 140 AB as distance increases. Since minor differences in drop are of little concern when shooting at longer ranges, the SA cartridge essentially matches the performance of the LA cartridge in metrics that matter out to 700, and out-performs at longer distances. Combine the lesser powder consumption, general precision of factory ammo and rifles, lesser muzzle blast and recoil, etc, and it's pretty clear why the 6.5 Creedmoor has gained such popularity for LR shooting/hunting.
> glad to see someone answered his question but in all reality how many could make that shot at a animal at 700 meters ? yes the 6.5 Creedmoor is an excellent round so is the old 270 Winchester ,the 6.5 Creedmoor is a better target round,with better bullets to use , and a better for a recoil-shy person too. but out to 500 yards the old 270 Winchester still will get the job done and has for many years.
