90 percent is very good kill shot percentage.
Hopefully anyone with a 30-30 would have a reasonable max limit. .338 Lapua maybe way the heck out there.
Broadside grazing at dawn, no wind, and you are prone.
And you believe there is a 90% chance the shot will kill the deer quickly.
I put 600 yards, mostly due to time of flight. Further out than that, I would be afraid that the deer might twitch and I'd miss. If the deer were bedded, I'd probably go out further.
How far would I shoot a deer?? About 1/2 as far as I would a wolf.
If the speed of sound is slower than the speed of the bullet, he will twitch on impact and then hear the bad news. Speed of sound is in the 1120 ft/sec range.
So, unless your bullet is attached to the front end of an arrow, you're cool. If you meant a random twitch, my point is moot.