I have 3 R22's....and none of them like the same stuff.
One loves the Winchester Dyna-Points, while the other two are only so-so with it. One loves..LOVES CCi velocitors, buy one wont print better than 2.5" at 50 with them. The third eats up mini-mags like crazy....and with this gun I get match accuracy shooting them. (thats the PSG clone)
You reaaly need to buy as many different brands as you can, then start there....there is no easy answer I'm afraid.