I am glad you have good luck with that method. But I think its telling you lies here. I found it to give very high numbers which translate to high pressures. But it been year and years since I did it. You know, like you use a stony point and find your seating to be 3.7" COL to hit rifling, but if you use the dummy case cut method, it raises that number to 3.8" to hit the rifling cause you jamming the bullet into the rifling. But you have the opposite going on here. Your getting low numbers. I use a Stoney point AOL guage. You yourself have to admit, something sounds screwy. Sorry I couldn't help further. Have fun.