My .223 Handi contoured barrel has always shot as well with Federal American Eagle 50 gr flat base hollow points as it does with the Win. white box. That's a good thing because the Federals are still available. I see them at Gander Mountain, Bass Pro and some local outfits, but not always! They are becoming scarce, as well. Groups size is typically in the 1" range at 100 yards. Sometimes I can get less and sometimes its more. It depends on me.
My Ultra .223 shoots the Winchesters best of any factory loads I've tested (which isn't very many). The Federals don't shoot as well as in the Handi. I've been saving the White box stuff for the Ultra and using the Federals in the Handi.