I guess what I'm asking is with just run of the mill FMJ is there really that much difference in a 300 to a 5.56. I love me some 7.62x39. But it suffers all the problems cited by 5.56 haters, it just punches holes too. Any of these will kill someone dead in one shot if its in the right spot but what advantage does the 300 have besides the fact that people love ARs and they wanted them to grow up to be an AK that they could dress up like a barbie doll.