I learned a long time ago that it is cost-effective to bed the rifle before you ever pull the trigger.
Seating de;pth is a very important issue, I will run a single shot if I have to, but a Wyatt's mag box in my Rem 700's solves all issues where I get .125 more COAL, and they do make a 4.000" length for 28 Nosler and STW's, etc.
Attempting to work up a super accurate load without flyers in an unbeded rifle is lunacy at it's best, depending on the stock.
Bench techniques to eliminate flyers are another subject.