I'm not a match shooter anymore (BR with 6ppc) but I do follow some of it on 6br site f-class open. Lot of good calibers such as 284 with 180gr bullets
http://bulletin.accurateshooter.com/...ome-built-gun/
Few years ago I have 284 build on a long action one of my hunting rifles and low 3000fps with 160gr bullet isn't bad and you got good brass for the 284 now.