B/C I have all I need w/260 and the 6.5x47L w/Lapua brass. Hard to overlook that option.
And as you mentioned - LR bullets, yep more options in 6.5 than 25 though I'd not be using a mid sized 25 at longish ranges.
Now in a 6mm - perhaps.
I do like the idea of a short 22 or 6mm ctg. that has a fast twist bbl - in factory options.
Thinking high BC.