Quote Originally Posted by Wm Dunn View Post
The coal listed is the length that it was tested at. You need to find your max coal to lands back off .015 to .020 normally and then , after building some dummy bullets find your working coal that the gun (automatic) will cycle with. That coal will possibly be shorter or longer than the coal in the spec to which you need to adjust the powder range amount (up if longer coal or down if shorter coal). This method is generally used for automatic pistols and rifle bullets can be a different conversation.
Well stated Wm Dunn