I re-barrelled my 260 after I shot it out in Creedmoor and I'm delighted , is it better past 500m than the 260 ? NO ! it's the same bullets at broadly the same velocities, you do the maths!
now this is subjective but I have found the Creedmoor to be easier to find an accurate load for , I don't know why ? maybe it's the case design or maybe I just got lucky but for some reason the 260 needed a lot more fettling to shoot well ?
factory ammo for my 260 shot just plain awful and I tried all I could get hold of ! the selection of ammo for the creed is broader and it all seems to shoot better ? for example the 140 eld-m hornady match will shoot ragged holes out of my rifle whereas the 260 rem stuff struggled to better 1.5 moa.
any off the 6.5's are about perfect for UK deer in my opinion.
all the 6.5's are great but the Creedmoor's success can be attributed to hornady supporting it so well with ammo , it's everything the 260 could have been if rem had supported it with decent ammo!