.308 can produce those velocities exactly in a 24" barrel if you're willing to use RL-17. For example on the 180 partition, .308 SAAMi max depending on your exact case and primer is about 50.5gr and velocity is 2820 give or take. I'll be the first to say that RL-17 is a little on the temp sensitive side, but then again so are N204 and especially N205.
You lose 30 ft/s going to RL16 if you need temp stability.
If you're going to try to explain how the .30-06 is so wonderful relative to the .308, you might want to try an example that the .308 can't do The gap is MUCH smaller than most people think it is.
Alliant lists a max .308/RL-17/180g load at 48.7g/2641fps in a 22" barrel.
Their load is for a longer spitzer/boat tail bullet - the speer BTSP is 0.1" longer than the Nosler 180gr PP.
As to the rest, you're in fantasy land. When you actually load to SAAMI max for both using good simulation software and a strain gauge to insure SAAMI max pressure, the gap is very small. Which should surprise no one who knows anything about internal ballistics.
The gap is MUCH smaller than most people think it is.
