I've taken neck shots with a muzzleloader cleanly, but would never try it with a crossbow. With a rifle- you can accurately place the bullet where you want to, and there is no "flight time" problem you have with arrows. Also, the shock of the bullet hitting the spine or near the spine usually paralyzes the deer and drops them on the spot. With an arrow, you have none of that- it's way too risky. I had a friend that took a buck with a crossbow neck shot- but it was not intentional- either his aim was off or the arrow hit a twig, but it hit the buck right in the spine and dropped him. Not something you want to intentionally try, though.