flattop johnny,
Welcome to the Campfire!
I think you would like the 6.5 Creedmoor a lot--or any of the other smaller 6.5's.
But I'd like to clear up a common misconception: Seating bullets so their bases are below the neck doesn't take up any more powder room. The base of a bullet takes up exactly as much space inside a neck as it does below the neck.
This is hard for many shooters to understand, mostly because they've been told the deep-seating a bullet takes up "extra" powder room for a long time. But seating the bullet below the neck is more the rule than the exception. In fact, a 200-grain spitzer seated to standard overall cartridge length in the .300 Weatherby protrudes almos as far below the neck as the same bullet does in a .300 WSM.
The reason the 6.5 Creedmoor holds just about as much powder as the .260 is not because the neck is longer, but because the shoulder angle is steeper, 30 degrees vs. 20 in the .260. This almost makes up for the slightly shorter case body of the Creedmoor. But the base of a 140-grain Berger VLD still protrudes 2/10th of an inch below the neck of the Creedmoor.
There are several reasons for the Creedmoor case design, but the biggie in bolt-action rifles is that the long, 3/4" ogive of bullets such as the VLD doesn't have to be seated partially inside the case neck, as it is in the .260--which does make seating the shank of such bullets near the lands possible.
