First time here, I saw this blog on google and wanted to add my side of the story.
6.5 creedmoor vs 308 is no comparison when it comes to cheating the wind even a 300 win mag doesn't stand a chance.
Here is some ballistic data for comparison.
6.5 creedmoor or 260 Rem bolt action with 30 inch barrel f-class rig.
308 palma rifle 30 inch barrel.
300 win mag with 28 inch barrel bench rest rig.
none of these are factory rifles.
All are safe loads either at or below chamber pressure max recommendations.
The ballistic data was taken from eskimo joe.com/-jbm.
70 degrees 70 percent humidity 10 mph wind sea level 29.92 in of mercury for barometric pressure.
lets start off with the big boomer the 300 win mag, shooting 210 grain berger vld at 2800 fps.
drop at 600 yards is 78.6 inches or 12.5 moa, drift is 20.4 inches or 3.3 moa
drop at 1000 yards is 294 inches or 28.1 moa drift is 63.9 inches or 6.1 moa
now to the 308 shooting palma required 155 grain bullet and I'll use berger since it has the highest bc value and since this is a palma rifle the speed is 2900 fps.
drop at 600 yards is 80.1 inches or 12.8 moa, drift is 27.1 inches or 4.3 moa
drop at 1000 yards is 323.1 inches or 30.9 moa, drift is 88.3 inches or 8.4moa
now the 6.5 mm bullet. either a 260 or creedmoor both have been about the same on the line.
this is a 6.5 mm 140 grain vld berger bullet traveling at 2900 fps.
drop at 600 yards 72.9 inches or 11.6 moa drift is 19.9 inches or 3.2 moa
drop at 1000 yards is 274.4 inches or 26.2 moa drift is 62.2 inches or 5.9 moa
Now add another 50 or 100 fps and you'll be shooting a 6.5 x 284 and the ballistics are even better but barrel life is now the same as the 300 win mag.
Now I will admit if you are shooting a gas gun it will be back down to the ballistics of the other two calibers.
Barrel life for the creedmoor or 260 is around 4000 competitive rounds maybe 5000 depending on how hot the loads were and cleaning regimen.
That's pretty close to the 308 barrel life.
now I have shot a lot of 30 cals in 300 saum, 300 win mag, 30-338, 30-06, 308, and I have shot some 284 cals in 7mmsaum (actually necked down 300 saum to 7mm to get long necks) I have shot the 6.5 x 284, I have shot the 6mm's mainly 6mmbr and 243, even 223's.
the creedmoor may just be my favorite as far as barrel life, low recoil, cost per round (including barrel cost) and the high bc slippery in the wind.
I use 7mm-08 winchester brass with no issues.