"If you had a lighter bullet you could start with the data for the lightest bullet you can find. Work up from there. If you have data for 85's then 70's should have less pressure with the same charge. "
Didn't realize this. I wonder if the lower in weight/grains you go the shorter, hence the jump to the lands become farther. The 85gr Sierra is .858, they sit in the case neck roughly .165 deep
. OAL is 2.650. So if the bullet was made even shorter because of reduced weight then the ogive would be yet even farther from the lands hence why the selection is based at a certain weight from lightest to heaviest?
Does that make sense?