The best advice I can offer is go with Norma brass. It's worth every penny. I went through several bullet/powder/load combos. Settled in on one with h4831sc and 150 Bergers would get several flyers. I sorted Winchester brass and even culled about 18 percent and still inconsistent. Switched to Norma same load groups got smaller and no flyers. Th 150. Berger is a great heavier weight bullet for the caliber.
In my RBros 270WSM I'm getting great results with WW brass, Nosler 140 gr. Accubond, Fed GM210M primers, and near max load of H1000. When working my way up in powder charge, POI was near the same for all charges.