over my yrs I have tried shooting a lot of inlines ( I am not a big guy into flintlock's and such even though I have owned and shot my share)
but have used all sorts of sabots with reduced sized bullets in them, and all I can tell you is every rifle has been different, what one might have liked another didn;t, and some times even certain sabots/bullet combo's needed work finding the right charge to get them to be accurate!
so, again, from my experience, finding what YOUR gun likes is key and then from there its about consistency in reloading and once you find what is accurate and has proper charge for the task being asked of things, bullet placement will kill deer with a 35 cal, 40-45-50 cal or what ever! as long as again, the energy level is there at the range your animal is at!
I think many people over think shooting deer, there not wearing body armor and any GOOD hunter should know where vitals are and where to place a bullet!
put a bullet in the vitals and they die, bullet diameter not the big part here, its having proper bullet up to task, and enough energy for the task being asked of the bullet ,