yes. there are differences in the 223 an 5.56. some rifles can't handle both rounds thats why the bushmaster, it can. so shootum up is the military 5.56 stuff and cutting one hole, good 223. $$$ is in the quality of manufacture, like most firearms. if your looking for rounds down range it may not matter as much, now if your looking to varmint hunt. one other thing is the mag capacities. nh is 5 rounds total for hunting.