What ammo are the rifles tested with?
I would be pretty unnerved I think to be shooting a rifle my life depended on it that rifle was a 5" gun with match ammo, and got issued 4" M855! I mean what would that combination work out to, a ten MOA gun?
I am really speaking of theory and worst case scenario here...I get that a gun that shoots groups that big would get pulled and tweaked. But not until after being detected! Even a 2.5 MOA gun, if it was 2.5 MOA with match ammo, might be pretty imprecise with 4 MOA ammo.
It's interesting to consider ammo as a critical component of accuracy...lots of guys I have known got very worked up about the technical requirements of a rifle to be very accurate, but didn't spend a whole lot of time thinking about the ammo it would be fed in the field.
Of course I have known guys who thought carefully about the whole package...but still you get fanboys for one maker or another obsessing about the accuracy of the 416 or SIG or whatever, and how they should be issued to all troops, but they don't then go on to talk about what has to change in the ammo supply in order to take advantage of that increase in accuracy!
OTOH I have seen guys who claimed sub-moa groups out of a stock 858 using Czech surplus...and since obviously that is eminently believable I guess the ammo isn't an issue.