Like Art, I do well out to 300-350 with my .223. I run 55gr Hornady V-Max's, Privi Partizan cases, small Win primers, and near max 26.5gr of Varget powder. That seems to duplicate the 55 factory Privi Partizan and Academy Monarch brass loads I chrono'd 5-6yrs ago- just much more accuracy.
What velocity do you get with this load?
What accuracy do you get at 100 yards?
I didn't think Varget was too good in 223.