Competition is one thing and I agree if that is what you're doing, you may need purpose built/custom built/better than. On the other hand, I've taken many 2-5 day rifle classes and most of the rifle/shooter combo's can't hold 3 MOA + it would be a rare shooter who brought an X Arc, Grendel, intermediate caliber at 2-3x the cost of 556.
But - competition, rooftop warfare, training class - I'd question how many rifles would give *demonstrably superior results*.
I don't have a Noveske tattoo or anything but to be sure a fan. I don't own any 6 ARC or DDF so no dog in those fights, but on balance, my experience with my 556 and Grendel Noveskes is universally sub MOA and as reliable as semi gets. Better is always possible, but I'd be curious to know exactly what is "better" that doesn't go into the realm of specifically being a game gun, in all seriousness.
Fukushima then we work our way up to Chernobyl loads.
!
