The 260 was a solution to a problem the didn't exist.
It served it's main purpose though, by selling more rifles and bullets
260 with a 125 gr Partition
.7mm-08 with a 140 Partition
Put a 120 gr Ballistic tip in the 7/08 if you want an equal comparison
Wrong, the 260rem provided a modern short action version of one of the best killing cartridges ever invented, the 6.5x55 Swede. Just like the 7-08 is a modern short action version of the 7x57.
Both are useful and effective, but I prefer the SD/BC values of the 6.5 bullets. Even at modest speeds, they have been working well for over 100 yrs.