I tried cast in the CZ 527 Varmint, 1:9 and gave up easily and early. It may have worked, but I wanted a 222, so that's what I got for cast and it's been easy.
My 223 is jacketed only, as is my 257 Roberts. Either will shoot same-weight Sierra HPs or Hornady V-Maxs equally well and to the same POI. I even tried to sort out which was better at one point and could not make one shoot better than the other.
I've always had a preference for any Sierra HP in any caliber, but Hornady HPs and V-Maxs seem to shoot as well for me. I've been tempted to try one of those boxes of 500 cheap 224s Midsouth sells but haven't gotten around to it because the couple hundred jacketed 22s will likely last me the rest of my life for no more than I shoot it.