@James:
Use any book data for N320 that you have for 115 grain jacketed bullets, start at the lowest end. You can use the same OAL I used above, 1.075, but I’ve run these bullets as long as 1.10. Keep in mind, that their profile is not conducive to guns with a short throat if they are loaded long. As long as you start at the minimum charge, and test as you work up, you’ll be fine.