"I think so, but ya never know.
The .260 (it's identical twin) nearly died off, but has regained popularity with the long range crowd."
Although ballistic "near twins", the 6.5 Creedmore is NOT an identical twin to the .260 Rem.
The Creedmore appears to be based on an improved .250 Savage case.
The .260 Rem is based on the .308 Win family of cases.
An identical twin to the .260 Rem is the 6.5-08 A-Square.
Identical or near identical twins to the .260 Rem would be the .263 (or .260) Panther (.243 case), the .263 Express (also using the .243 Win case) or various 6.5-.308 Wildcats.