For the downvoter, it is a myth that you need bigger than 5.56 to hunt deer, looks like hunter associations are banning it just to motivate that they get to keep their even more power guns.
For example this requirement looks like it was explicitly made to forbid 5.56mm cartridges, they are not even mentioning energy:
> The cartridge must fire a bullet with a minimum diameter of .243 inches (same as 6 mm).
For example this requirement looks like it was explicitly made to forbid 5.56mm cartridges, they are not even mentioning energy:
> The cartridge must fire a bullet with a minimum diameter of .243 inches (same as 6 mm).
http://www.eregulations.com/indiana/hunting/deer/
But for example in Sweden you are allowed to hunt the same size of deers using weapons with half the power of 5.56: 800 Joule.
Only things you need bigger bullets than 5.56 are brown bear, moose and red deer which requires 2000 Joule.
And if you think it is inhumane to kill 50kg deers using 1600 joule bullets, how many joules would you require that people use on a 700kg moose?