Rio, Cheddite, Hornady(which are Cheddite), fiocchi, and federal are straight walled hulls. I load my rangefind hornady, and my Fiocchi hulls like Federal hulls using Fed wads or Calybuster copies of them. I don't push max, because I've found to many differences in components. Claybuster wads aren't exactly like the originals they copy. Especially when using slugs in them. I meassure the base wad thickness of the hull to compare identical looking hulls, figure if it's straight walled or tapered, and that narrows down your load data, even lets you check it against similar hulls. I compare data to get what I feel is safe load data, then try it out.