As long as the hunter obeys the magazine capacity and minimum caliber size restrictions (where applicable), what difference does the rifle's appearance make? IMO, an AR-15 makes a fine coyote rifle, and a scoped heavy-barrel variant will pop groundhogs all day long. Although I've never killed a deer with a .223, I have used an AR clone (Bushmaster) on several feral pigs.
The pork chops and roasts were delicious.
When I think of a "hunting rifle" I think Pennsylvania Rifle, Hawken Rifle, Winchester, Sharpes, bolt action Wheatherby, Remington, etc. - not a Colt M-16 or Garand or M 1917 - although I shoot the latter and think them for quite useful for - other purposes.