"Conventional wisdom" would say that the once fired, fire-formed to your chamber brass, with uniform neck tension, would get "better" results, than raw unfired brass. If I were you I would look for run-out issues? In my experience, new necks are pretty straight, fired cases right out of the chamber are pretty straight, if your chamber is, so perhaps something in your sizing or seating sequence is creating excessive runout? Even just rolling the case on a flat surface, like a mirror, can show runout - case mouth wobbling, bullet tip wobbling. Don't really need to spend big money on a new gizmo, at least until some evidence that there truly is a problem in the first place. As per a post I recently read on this site, checking for runout, is not so much to come up with cases to "fix", as it is to identify where your re-loading process can be improved to not create it in the first place. Also possible, I suppose, that your neck in the chamber of your rifle is crooked - new brass is straight and shoots well; fire formed brass now crooked - will not know unless you check it.