I was performing some reloading tests another day for my .223. Tried two different bullets over a large window of powder charge, leading to 16 groups of three shots, 5 charges on another bullet and 11 on another one. Not a single group was over MOA, and several were less than 1/2MOA. I think it is a real PITA to try to consistently shoot 1/2MOA groups, would at least be for me no matter how accurate the rifle, but keeping it sub MOA doesn't seem impossible. After all, sub-MOA is enough for almost any real world hunting I do.
When shooting from less than perfect position (=not bench or prone with bipod with a rear bag), I'm really struggling to keep anything under MOA. This is what I really should practice more.