Originally Posted by The_Kid
If you can't find a bullet to fit the bill from this,
you're doing it wrong.
It "comes down to" when does the projectile's speed reach transonic; which the 270 stretches 300 yards further, (using sane loads.) After that is "comes down to" and which bucks wind best; which the advantage again goes to the 270.
"Shooter confidence" is always higher when physics are stacked in the shooters favor.
How can you use the same load when the 2 have nothing in common except the base diameter??
Here is actual data, now the .270 is using a 160gr while the .308 is using a 168gr match as there are no match bullets for .270. MV in the .270 is 2650, .308 is 2700. I am rounding both down. The .270 by 30fps and the .308 by 50fps because no one uses max loads often.
Bullet drop in inches w/ 100 yard zero:
.270 at 250 yards, -9.6, 350 -24.1, 450 -48.3, 550 -83.3, 650 -131.6
.308 at 250 yards, - 8.5, 350 -22.9, 450 -45.9, 550 -79.1, 650 -124.8
Not sure what physics you were talking about that pertain to accuracy. They both shoot pretty even. I'm not seeing a 300 yard advantage at all. All loading data is from the Hodgdon site, everything calculated on a JBM calculator.
With 150gr ballistic tips the .308 has the advantage again in MV by 100fps+-
.270 at 250 -7.6, 350 -20.6
.308 at 250 -7.1, 350 -19.3
The long bullet of the .270 may perform better on game at distance, but not on paper.