Ok,
So I put a Lilja AR740 barrel on my AR...
I did the 'ol load .5 grains under max and see how it operates with Hornady 68gr BTHP Match bullets, W748, and 556x45 NATO brass.
It's the first time I've ever gotten 6 inch groups. It was BAD! REALLY bad...
XM193A was good.
Nosler 55gr BTBT...