I have hunted moose with the 6.5x55, with the 140 X bullet (favourite load of the Remington 700 Classic I had at the time), but have carried other rifles for black bear, because I like a larger, heavier bullet in a shorter, handier rifle for bears (not that the Swede cannot kill a blackie). I'm on my 4th 6.5x55 rifle...finally getting a left handed Sako! First 3 shots out of this rifle went into 3/8" at 100 yards!
Have more trigger time with the 6.5x55 than any other centerfire cartridge; love it!
Only animal taken with my left handed Browning X Bolt in 6.5 Creedmoor has been a bull moose. Did not find the 143 ELD-X bullet inside that moose, but then again, the shot was only 20 yards!
Looking hard at the 6.5 PRC right now...may rebarrel my 300WSM...or I just happen to have a LH Montana 1999 action that I can use for this!