This question was just asked on a competition forum, here is the answer given by the fellow who just won the F-class (TR) National. The custom actions he talks about are the RPA, Benard, Stolle, etc
All actions are the Rems 700, Win 70, Savage etc. Hope this helps.
F-Class Open.....................6.5-284 Win Caliber, Custom Action, F-Class stock
F-Class TR........................ 308 Win Caliber, All Actions, Tactical/F-Class stocks
Service Rifle.......................223 Rem Caliber, AR-15, fast twist barrel
Palma................................308 Win Caliber, Custom Action, Palma/Highpower stock
Any Rifle............................6.5-284 Win Caliber, All Actions, Palma/Highpower stock