Originally Posted by
JD300
Ok OK so to follow up I run some numbers, I used inexpensive ammo from the same manufacturer, $46.00 Each per 20 rounds from Gunworks. loaded in similar ways (As close as you can get between two calibers)
.308 Winchester, 150 Grain SUPER X Muzzle velocity of 2820 FPS
.270 Winchester, 150 Grain SUPER X Muzzle velocity of 2850 FPS
For these purposes as I could not find it on the winchester site we will assume test barrel to be 24" this is pretty common I believe.
My research also found that a 150gr .270 lost an average of 32 FPS per 1 inch of barrel
And a .308 150gr lost an average of 22.7 FPS per 1 inch of barrel
So chopping to a 19" barrel for both would yield you.
.308 113.5 FPS loss of speed
.270 160 FPS Loss of speed
I will post the ballistic charts from my phone to follow.
Very interesting.