This is the 6.5x68. What can you tell me about it? I saw another online source claiming 3300fps with 140gr. bullets and a 26" barrel. Is that just internet banter or real?

I'd say 3200 is more likely with the 140 in a 26" tube.

Very cool cartridge though!

The RWS reloading manual lists the 6.5 x 68 with a 139 grs SP bullet with 3020 f/S. The loading data of RWS are very conservative but far away from 3300 f/s. Barrellength is 23,5".

3300 is pushing it and not recommended. It's the euro 264WM basically in performance. Can you get there in a solid rifle rolling your own? Yes but with the price of the brass I would be looking to treat it nice.

The 6.5x68 case design looks like it would really stretch if loaded toward maximum pressures.

Jeff