I’ve read that Federal ammo is dirtier than others but I don’t know if this is true.
I really need to know what company ammo is the best.
Stick with Winchester and Remington, and you should be fine.
With the .22s, I've got a bunch of bricks of Winchester I bought years ago, and they do just fine. I also like CCI for .22LR.
Buy a 50 round box of the major brands and see how they feed in your new rifle. Go with the one that feeds the best.
/johnny