Re: P.O. Ackley rifle
Cartridges of the World, 2nd edition, mentions a 25 Krag, which was a 30/40 necked down to 25. That'd be pretty close to a 6.5mm. It also says there is an improved version, developed by P. O. Ackley, about 1946. Doesn't give any info on the Ackley version, though. Just kinda throws it out in passing.