If you want combat accuracy, BCM will give you that and more.
Are they found on national match guns out at Camp Perry? No, but then, they aren't intended for that.
I'll say it again: my 16" BCM upper is every bit as accurate as a person has a right to expect from a 5.56mm chambered combat type barrel. Not a 20"+ HBAR in .223 with a tight chamber, but that doesn't seem to be what you want.