jump or jam
Don is one of the best ,,,but just because his/a bullet in his rifle with his powder and powder charge like to jump does NOT mean it will work for your particular combo,,,every new shooter asks the same ???,,,that is the beauty of benchrest,,,you have to tinker/experiment to see what is good for you,,,its like the newleywed hubby asking the old timer ,,,"what will my new bride like in bed ?"....the answer is ,,,she will tell you ,,,the same goes for your rifle,,,,I "think" the type/brand of powder is also a factor in the quest for the perfect seating depth,,,some powders like to jump and some do not,,,,Roger