@
Akj
The fellas on this site, and at least one of the sites you’ve posted the same question on, are mostly telling you to do the same thing.
Use a .308 Win.
However...
If you model 6.5 PRC vs .270 Win vs .308 Win, which I recommend you do, you'll see that in reality there's 2/10ths of bugger all between them with a 18" barrel.
At all ranges, you're looking at a terminal energy delta of ~5% more or less, depending on bullet and how fast you're prepared to push it.
The .270 and 6.5 will fly a bit flatter, but not by a great deal. A couple of inches difference at 300m isn't a gamechanger one way or the other. The sectional density is roughly the same give or take. They all burn pretty much the same percentage of the powder charge (mid to high 90s).
The only tangible variables that makes the .308 Win the more logical choice in my mind are (a) less muzzle blast and (b) bigger diameter hole. But at the end of the day, it's what you do the moment you pull the trigger that's really gonna make a difference.
So in many ways your question will succeed in one aspect - making a whole bunch of guys around the world spin their wheels arguing over bugger all difference. But it will fail to deliver a definitive answer.
My answer is: If you already have a .270 and all the associated gear, then stick with it. Add some illogic to the equation ("I want a [....] for no real reason other than just wanting one"), then get it and be happy. You certainly won't go wrong with a .308 Win - it's the most proven short barreled medium to large game hunting rifle ever, period.
(I shoot a shed load of red deer every year with a 18" .308 Winchester and couldn't be happier. I'd never own a .270 Winchester even if Ryan gave me one for Christmas, but that's just me.)
Bookmarks