If you look on your Steyr test target it will tell you what size pellet it was tested with but not the make, both mine were tested with 4.49, and the make? I'll let you in on the open secret, JSB match.
Group sizes can be significantly different, make to make, and pellet size, if you can aim at a ten and hit it (even if its only one in ten shots!) why lose it because of a pellet that does not group? At £7 a tin, 60 shot match costs 98pence, how much did your gun cost?
If you are glad to group in the black and hit tens by luck, use any thing, if you can aim at a ten, call it a ten, and hit it, buy the best for your gun. If its a Steyr its probably JSB match 4.49
Good shooting.
Robin