This out of a 10/22 with a Green Mountain 20" bull barrel, upgraded extractor, and Mueller APV scope at 50 yards off a bipod:
Federal blue box - most accurate, feeds well, a few failures to extract. Will put 5 rounds under a dime at 50 yards. Easily. It is more than likely more accurate than I am.
Winchester Target - VERY close behind the blue box in terms of accuracy, no failures of any kind
CCI Hypervelocity - Wont group well at all at 50 yards - Couldn't get 5 rounds under a quarter. No failures of any kind.
Rem bulk pack - Blew the extractor out of the gun when it didn't seat fully in the chamber, blowing out the side of the casing.
Can't attest to accuracy because I refuse to use it in the nice gun.
Winchester XPert - Wouldn't seat in the match chamber of the barrel. No further data - Didn't want to replace the extractor again.
I still would like to try the CMP Aguila stuff (I've had good luck with their ammo in the past, but have never tried it in this gun) as well as some standard CCI.