My question is: Do you reload? With the possible exception of 6.5 Creedmore, the rest of the 6.5's are mere shadows of themselves in terms of performance if you are limited to factory ammo.
I like my 6.5x55's a lot. The .260 and Creedmore would be pretty comparable.
I have a 6.5-284 that I went to a lot of trouble to build. Many people make the claim that the 6.5-284 gives you .264WM performance in a more efficient case. I find that to be a bunch of BS in my rifles, unless I really push the pressures hard. I am underwhelmed by the 6.5-284. It does have a performance edge over my Swedes, but not by very much. If you want a 6.5-284, get it in a Savage. It's a no fuss, no muss way to obtain a 6.5-284 and the barrel is easy to change if you are not happy with it.
I have a Winchester Model 70 sporter in .264WM. It is far and away my favorite 6.5, in part because I like the rifle so much. It is still undergoing load development and I don't believe the barrel is completely broken in yet. So far, it is shooting Nosler Partitions very well. My next step is to do load development with Bergers and AMAX's. Now that I have it, I wish that I hadn't gone to the trouble and expense of building the 6.5-284. Of course, this rifle wasn't available when I did that. Neither was the Savage.
With all due respect to previous posters, I don't believe that the 6.5 Grendel belongs in this conversation. That is not to say that it is not a good cartridge or that you can't kill a deer or antelope with one. It is a great cartridge in an AR or a compact, ultra light bolt action. Outside of that realm, it gives up too much performance relative to the larger cased 6.5's IMO. From my point of view, the 6.5's are at their best with the 140 class bullets. The Grendel is incapable of pushing the heavier bullets to useful velocities, which deprives it of a lot of the virtues inherent in 6.5's. I still REALLY want one in an AR, though.
