Having tried CCI, Winchester, Eley subs (40g HP) I have settled on Magtech, they seem to have the edge for me (just) and are about the cheapest of the lot which can't be bad.
Fast ammo is difficult but having used loads I'm happy with Mr Remingtons Yellow Jackets (HP). For a real thump I use CCI Velocitors, other very fast CCI stuff produces poor groups (the Velocitor isn't brilliant).
Need to add that although I shoot Short Siberia 200yards target with the .22 (surprisingly good results, most commonly Federal 40g solid) it's primary use is hunting!
Tool is:- CZ Bolt Action, Fu