Recommended pellets for .22 s400 XTRA FAC ?

[nico243]

Hi folks just acquired a nice single shot .22 s400 extra FAC, with power turned up it is producing around 28 ftlbs what pellet would you guys recommend, have tried BIS MAGS and AA DIABLO FIELD both performed pretty well (the AA's just have the accuracy) are there any others I should consider, I ask as I don't want to end up with several tins of useless pellets that don't suit the the rifle.
I guess I'm after accuracy and velocity rather than accuracy and heavy thump, what would you guys suggest?