If you are going to go long action, might as well do a 6.5-06, 270, or 280.
No messing with rim sizes, low pressure load data, varying twists, throats etc.
Short action, go with 260 or Creed.
None of those three long action cartridges match the recoil level of the 6.5 Swede and .25-06, and .277" bullets don't match the ballistics of 6.5mm bullets. There's no free lunch.
Also, why not load 6.5x55 to CIP levels (i.e., approx. 55 kpsi) in a modern bolt action? Shouldn't be that hard for one to figure out what loads are in that ballpark, and targeting the CIP max pressure of approx. 55 kpsi, or some lower level, still provides a substantial safety margin to keep one away from pressures where knowledgeable people start being concerned. In fact, I know of at least one European manufacturer that has published 6.5x55 data reflecting the CIP max pressure rather than the anemic SAAMI max pressure.
If you're having a rifle rebarreled or custom-built by a decent gunsmith, it shouldn't be that hard to get things right for a 6.5x55. Stick with one type (brand) of brass, make sure you get a 1:8" twist, and specify your rifle's throat or simply figure out the throat once you get the rifle.
The 6.5x55 cartridge is a model of both effectiveness and efficiency with the powders and bullets currently available, and even before the great powders and bullets we have now, it was a model of effectiveness dating back over 100 years.
