A little late to the party here, but for future reference... rather than pick a zero out of a hat, so to speak, you can use JBM or Strelok Pro to calculate your Max Point Blank Zero and Max Point Blank Range.
Basic idea is you put in your load data and the maximum acceptable radius (or diameter, I don’t remember for JBM) for your application. Like, if you’re shooting steel plates that are 8x8, Max radius is that of the inscribed circle... so 4 inches, maybe 3.5 to be safe, and the calculator will give you both the maximum range that you can get away without holding over/under shoot