Not a hunter yet, but interested in moving that direction...
Neck shots. Assuming you are still talking lateral and not severing the spine, isn't that a less humane way to go? Unless you are lucky to get the arteries on either side or the spine, isn't that shot, incapacitating though it might be, a slower way to kill?
I would think lateral shot to the shoulder blade going through the lungs/heart would be the best shot. I'm just talking, not arguing.
.45acp, .40 S&W, 9mm, .38 Spl, .380 acp, 22lr
12 gauge, .223/5.56x45mm, 30-30 Winchester
2 Chron. 7:14 Christians must seek His face