Max SAAMI OAL for a 260 is 2.800"
Max SAAMI OAL for a Creedmoor is 2.825"
Both are screwed trying to seat the pressure ring of 147 Hornady above the neck/shoulder juncture and keep in a 2.800" mag box of a 700.
Maybe if you get technical about it, but the Creed powder compression under the 147 is quite a bit less than the.260-at least in my rifles-because of the design length of the casing. I seat them both to fit the standard 2.8+ magazine and the Creed handles the longer bullets much easier-although, I have also used the 147 in my .260 without issue. Like I said before, it is a wash for the 130-grain bullets and the .260 actually gets a bit better velocity. For the heavies, I will take the Creed every time, unless it is with a longer magazine, then it is again a wash.