Ammo
Gustav: Federal 711B.
What kind of match shooting do you have in mind? Prone, 3 position, BR-50, Silhouette? Just curious about that.
There's no definitive answer to your question because firearms tend to be quirky as far as what a particular gun will shoot well.
When setting up a gun for competition, I always buy as many types of .22 ammo as I can afford - typically 12 to 15 types of .22, from cheap to very expensive. Sometimes the less expensive ammo works as well or better than the high end stuff. That is the case with my Bullseye .22 pistol.
My two match rifles showed a preference for Federal's subsonic match ammo.
The original Gold Medal subsonic (900B) does not appear to be available (too bad as I'm down to my last brick) but the rifles also shoot the 711B quite well. That is what I use.
That being said, it was a while ago that I set the rifles up. There are more brands and types available now and I should test again. It'll be a good indoor project with a Spring time follow-up.
Pete