I might consider the Montana 1999 action, which is sort of a Mauser/Model 70 hybrid. If you are planning to do the work yourself, they are incredibly simple to barrel - just cut the threaded tenon. There is no counterbore, breech cone, extractor cut, etc.
The case head diameter is a little smaller than the typical .308/.30-06 family of cartridges. I don't know if they will work reliably or require bushing for proper function. I think Remington 700 bolts are easy if bushing is required (having done this before for 6.8 SPC based cartridges) but then there's the problem of the extractor which usually requires cutting the bolt for an M16/Sako extractor.
Assuming that you want a blind-magazine fed rifle, you may need to make some modifications and adjustments for proper feeding.
The bore diameter on 6.5 Carcano is a little different than a standard 6.5mm in use today. Looks like the specifications make it a difference of almost ,1mm (about .0035). It sounds to me like maybe the better option if you're reloading is to use a standard 6.5mm barrel blank and hand-load modern 6.5mm bullets? Definitely a specialty project either way. Your other option would be to try to look for a 6.5mm barrel blank that has a .266-.268 groove diameter for shooting original bullets in it. Maybe you could try to find a take-off original barrel that has enough meat left at the breech to cut off the chamber and re-machine to your rifle.
Once you have the barrel blank, you'll need a reamer and a set of headspace gages to machine the barrel to your rifle. If you're having a gunsmith do it, you're likely to have to pay for these because they're very non-standard calibers to have and it's not likely the gunsmith will be able to justify buying them.
Those are just the things that come to mind for me. If your nostalgia for the cartridge is worth justifying all this additional work and cost, it would be an interesting project to see completed. But not a cheap one - I believe it would be well into the thousands (with an "s") dollars range.