I hear you on the ammo shortage.. I wish I could try a couple other varieties but alas, none are available around here.. I've worked on the trigger on this rifle to give a decent, 2.5# break.. Helps groups a lot..
Of those I have, the Winchester HV Varmint 30g did the best in this rifle.. I'd love to try the Norma stuff.. Might have to get some online and see how they perform.