The only trouble with the 6.5x68 was the 12" rifling twist in normal factory rifles chambered in that round in years gone buy - unless that has changed in the last few years.

I re-chambered a M96 to 6.5x68. I kept my loads on the low side, with 129's running 3,000fps, not the 3,300fps my buddy was 'getting" in his re-barreled and chambered m1917 Enfield.

The only thing I shot with it, was 2 snowshoe hares - 1 shot. They were 210 and 220yards from me, one directly behind the other, on the Bowran (logging) Road. Pow - 2 bunnies down.

The un-chamber a loaded round, I had to partially pull the bolt.
Gunsmith by the name of Arch chambered up a 6.5x55 to .264 Win, Mag once. Noted in Ackley's #2 book, so I did a similar thing.