6.5 has less felt recoil to me. I reload now though so it's a moot point. If I had to do it over I would probably have gone .308 just for ammo availability.
I wouldn’t get too worked up over this thread. If you look at the original question it doesn’t mention anything about cartridges, just caliber .308 vs 6.5. Without more details from the OP (who has only 11 posts) it is just a .44 mm diameter difference. For all we know the OP could have two different chambered rifles, one in 6.5 Grendel and one in 300 RUM and could be shooting from 50 yards away.
No need to continue this thread as things like this have been beat to death a thousand times and there isn’t much advice to be given or argument to be made without more details.
6.5 easier to shoot and I've killed more than malaria with mine. 6.5x47, 6.5 creed, 260 rem they are all basically the same. 308 was developed for the army because it was cheap.
I had to make this decision recently and went with 308 based on ammo price and availability near me. I wanted the 6.5 for the reduced recoil but it's hard to find sometimes.
There are plenty of resources out there crunching the numbers that play out why 6.5 is superior ballistically and it has less recoil so it's easier to shoot. You don't need more bullet diameter than 264 for muleys so 6.5 wins for me. That is not to say that a 308 wont work just as well for nearly all hunting situations and shots that most hunters should ethically be taking but the question wasn't if either would work, it's which do you prefer for mule deer. 7/08 is another step on the continuum of benefits between the two that is a nice choice too but maybe with less ammo availability?