Re: I shot a ladder test for my STW
to shoot the ladder and get any meaningful information it requires a chrono to spot the nodes and to go up in about .2-.4 increments on the powder. I like to use .3 increments.
harmonic nodes will be spotted by both groupings of bullets and the MV will tend to group. For example they might be 10fps apart for say three rounds and then jump to 20-25 on the 4th shot and it should impact away from the previous group.
Each ladder can only work one component for variation. Most tend to know what case to use, what primer and what bullet. The variable is powder charge, seating depth and neck tension.
I start with the bullet jammed in the lands for the ladder. That way I know I am looking at max pressure curves when shooting the ladder.