A lifetime ago, Elmer Keith wrote that the most reliable bullet performance and penetration comes from cartridges that start in the 2400-2800fps range,
Obviously this was themed on the bullet designs of the time but I can say that I have noted the same thing apart from the exception of bullet speeds that go way past 3000fps with the .257 Weatherby being a good example. Savvy handloaders who have been using tough 120 grain bullets in the 7mm Magnums will also have noted this.
But, high velocity isn't the only difference and yet it still is, relative to caliber and bullet weight, an example being those familiar with a .375 H&H performance as a step up over .30/06 level of performance as a recognizable jump many comment upon, but it happens again when the .460 Weatherby is used. These 3 levels tend to revert an experienced person to think that most everything from 6.5's to .338's are more similar than dissimilar to the performance of a .270. They tend to lump together as a performance category and you see that here whenever deer or elk cartridges are discussed, because they all do similar work when well delivered.
So, I would recommend simply looking for a load that little 6.5 digests that proves accurate and then concentrate on placing it as well as you can and that is the reasonable value you can expect from that cartridge. Setting personal goals that push things to the endth limits only causes stress and wear on the components of the build, starting with the brass. Enjoy the rifle and worry less about the load as most 6.5mm bullet will do what 6.5mm cartridges are commonly used for.
