As with anything else the more they are hunted the wilier they get. I've hunted them free range where they show little fear of humans and high fenced area where they are wild as hell. A friend use to hunt the king ranch. The rules were that one must kill two does before killing a trophy buck(5.5yo 10+ points) or a cull(5.5yo 8pts or less. The does were skittish as heck and good 10+ point 3.5 and 4.5yo would just stand and look.

"It's not how hard you hit 'em, it's where you hit 'em." The 30-06 will, with the right bullet, successfully take any game animal in North America up to 300yds.

If you are a hunter, and farther than that, get closer!