Soon to be getting one in .177 calibre, my question for those who've owned one- are they particularly pellet fussy?

I plan on starting with AA Field or JSB Exact, but probably with 'test packs' of 50 each so I can try different head sizes of 4.51, 4.52 & 4.53...

I know all rifles are different but any pointers for common 'likes' pellet wise would be appreciated.

Cheers