nicholas,
ironically, i am also making a 9.3 wildcat. i am starting with a 9.3x74r case, kind of ackley improving it. slightly shorter neck, sharper shoulder moved forward with less body taper. i don't know what it will end up doing, am hoping for 200+ fps.
i am going to put it in a valmet 412/512. the rifle has adjustable regulation. so, my hope is that i will end up with a rifle that will give me 2500+ fps with 286 gr bullet. also, one that will regulated to a workable grouping.
mine will be a 9.3 x 74r improved. i looked for someone to have done this already (i wanted to rent their reamer) with no luck. soooo......i ordered one a couple weeks ago. then a set of custom dies, etc.
i did a simple calculation with the dimensions i had and it said there was a 14% increase in case capacity.
my thought is, there are lots of 9.3x74s out there, might be a couple guys that want more. my intention is to use an o/u rifle platform and one that is adjustable. might be a dud, but will not have destroyed a $10,000 rifle. my guess is it will work, but will see.
good luck on your project!