One of the lads here, now passed away, used a Ruger #1 chambered in .300 H&H for the 1,000 yard winter match at Burns Lake, many years ago. He won the weekend-long 'match' for best 3-shot group.

Yes - it was an anomaly, a 'lucky group' but his 3-shot 1 1/2" group still won the match for him.

Richard's usual 3-shot was 1/2 moa, around 5". Still not
shabby at all, for a sporter at 1000yards, let alone
chambered in a rifle not known for accuracy.