I seem to recall that in the early-1960s that Sierra gave some kind of an award for a 10-shot MOA group with their bullets. At that time, I was a regular at Bob Hutton's range (Hutton's Rifle Ranch) in Los Angeles. If you could shoot a 10-shot MOA group, you could shoot that rifle at his range for life. He posted each qualifying group on a bulletin board.
Your question is probably best put to Dave Brennan at Precision Shooting Magazine.