I do my own load development. I use pretty good equipment. Some of the posted ES I see are unicorn level. If the dude is paying $5 a round, that takes Approx 46 rounds to cover the cost of his magneto sporter and teslong. Shoot a few rounds at distance to verify it shoots or doesn’t shoot.
Erik Cortina made a big deal about his just over an inch group at a 1000 yards that he filmed. That load he shot over the chrono had a 20+fps ES. It’s easy to plug shit into a calculator and try to determine results. Shoot it at distance and see what it does.