John - a while back (few decades) I re-read the article in one of P.O. Ackley's books (#1 I think) about an Wildcatting experimenter named Arch. Arch had his own version of an improved 6.5x55 for the Swedish Mauser rifles, but had experimented with one opened up to .264 Win.Mag. & noted the
old 96 action was a lot stronger than people gave it credit for. The 98 was indeed an upgrade, in the large ring variety, due to the better gas handling in case of a pierced primer or case failure.
Well, I figured if he can do it, so can I.
I got my buddy's reamer and opened mine up to 6.5x68.
Now, it was a 2 shot only, which was OK by me. The bolt would "just" close over a round sitting a little bit cock's eyed in the magazine.
The only drawback, was that to remove a chambered round, you had to pull the bolt out a bit. NP
I didn't work up full powered loads in it, but felt a 129gr. Hornady at 3,150fps of so, was fast enough.
Buddy Keith was running those at 3,300fps in his 6.5x68.
The only thing(s) I shot with it as a pair of snowshoe hares on the road, 210 and 220yards in front of us, one perfectly behind the other. One shot, 2 rabbits. Killed them both, DRT. It looked like 1/2 (base) of the bullet went through both shoulders of the second one, after bouncing off the road at approx. 215 yards from the truck.
edit: I forgot to mention, my rifle still had the 29" bl.
The 6.5x68 is one hell of a bunny round - 2 for one shot.