Huge waste of money developing and testing it. 7.62x39 would be a much better combat round if we needed to go in that direction, and there is almost an inexhaustable supply of it in existance. I'm not so sure the .22 poodle shooter round currently in service lacks the stopping power as urban legends would have you believe- even the russians have gone to a .22 rifle round in the AKs, and its not because of political cronyism, industrial bribes, or because they they like developing inferior military equipment that they ended up there.