If you hunt in a state that allows rifles, I think you can use the AR style guns for deer. My wife's uncle has gotten into building AR's from scratch. My little brother is getting out of the Army in a couple months, and he just bought a S&W AR in .223. It's friekin awesome... we were shooting last time he was home on leave. i was popping a steel plate at 200 yds with iron sights. I REALLY want one now. Plust it'd be sweet to use on coyotes.
"When a hunter is in a tree stand with high moral values and with the proper hunting ethics and richer for the experience, that hunter is 20 feet closer to God." ~Fred Bear