I have posted this pic before of these two bulls - shot the last rip to the range with my AR 15. They represent 20 shots fired from the prone position with iron sights. The strings were fired consecutively in a period of about ten minutes. Neither has all 10 in an MOA group.....but a really good shooter would do that, probably all day long.
The first target - on the left - has only seven shots showing. The other three are in the seven and eight rings and out of the pic.
I wasn't trying for a good group; I was trying for a good score.
The point is that, if a duffer like me can get this close shooting with irons and from an off the bench position, then putting a scope on the gun and bench resting it will very probably produce that MOA shooting that y'all are writing about.