Is there any dif in each??.A NE vrs a HR??.My gun is a NE Ser# starts with np.Its a sb2.What can yall tell me about it?.Please help.I looked a the FAQ and got lost lol.Thanks guys,an old man sure needs some help.Some of us get confused easy when new stuff comes along,lol.I want to get some barrels for it & im at a loss on what is safe.Rite now it has a 243 cal.bull barrel on it.Bless yas,pan.