I suspect the rim on the .307/.356 had a lot to do with the ability of the M-94 to work the cases through the magazine. The cartridge stop on the link is pretty sensitive to rim diameter.
The .250 Savage tapers .054" form the base to the shoulder. The .307/.308 tapers .016" form base to shoulder. I suspect the straighter case wall helped extraction the most.
I think the slightly Improved .250 Savage because of its smaller case capacity, would work well in both models of lever action rifle and provide an interesting increase in performance.
