Tim -
Strictly speaking for myself. When/IF I don't have any idea of where to start on COAL, I've found that the FACTORY coal is NOT a bad place to start.
Alot of folks say they start by finding the lands and backing off +/- .1". Some magazines won't allow that so....
I start at the max that will function thru the magazine.
This is what I do.....so hope it helps.
Jerry