I'd be surprised if anyone is hunting deer in PA in .223 caliber. They don't allow semi-autos for deer hunting in PA, and bolt/pump action AR-15's aren't exactly common.I think so,but it is legal to use in NY I think...its the bare minimum caliber you can use in PA for deer!
Do a search for .223 and deer hunting in the forum, I know this subject has been debated extensively here in the past. With good enough shot placement I'm sure one could argue that smaller calibers are adequate. However, I've read a number of times in several places that the .223 was designed primarily to wound.