I've got quite a bit of experience with 6.5mm's, and the Ackley Improved just won't give you much in terms of a performance gain on game animals vs. the .260 Rem.
For shooting deer,antelope and the like, the .260 Rem is as close to perfect as a cartridge can be.

Now the 6.5/06, and especially the 6.5/.284 are real improvements, and there is plenty of loading data available for both.

Just as an aside, the 6.5mm/.284 is one of the most accurate cartridges around. And it absolutely hammers game up to and including elk at ridiculous ranges. I would lean this way in a short-action, 6.5mm wildcat.

Good Dogwork and Good Hunting