Aaah, the pellet conundrum.
The best grouping pellet in my steyrs were JSB express followed by the AA but they both became unpredictable when the wind blew. Not sure of the current batch numbers i have but he ones i got from the Czeck guy at the worlds seem to be fine along with a sleeve of 40000013 (i think)
Just to give a bit info on barrels vs pellets....
3 different Steyr's, 1 LG100 and 2 LG110's
One likes 4,51...the other 4,52 ......the other 4,53