It's different for different calibres and different weights within the same calibre. I email the shit out of Barnes when I get a new rifle about reloading information. Out of the same cal reliable expansion might vary by up to 300fps with 30 or 50 grain difference in projectiles. This thread doesn't need to exist, there are always going to be people that complain or don't like something irrespective of what it's like. Use barnes as they're designed and you won't go back.