10 with 80-90 grainers or a 12 with 60 -70 grainers? And out to 500 -600 yards. Logic tells me 10 with 80-90 grainers and anything heavier would take an 8 twist futher out beyond 600... Am I correct?
I apologize for being blunt but no, it's not correct. I'm pretty sure I know why you're uncertain about a 10t being sufficient but instead of me guessing at it, explain why you feel it's insufficient and then we can get to the bottom of it.