Your load book/source should state the tested/suggested COAL. If you go shorter you're going to increase pressure.Plated round nose. I ran about five charges that all came in at 6.4 before I started loading. I then checked the charge after loading the ten test rounds. The loads at 6.2 had very little if any cratering. Which leads me to believe I need to stay longer than the initial 1.125 oal.