[Unclenick]

No doubt the PM will make for easier shoulder length reading as it gets you out of having to balance the head of the case on the caliper. I have them in .223, .308, and .30-06, which are what I load most of, and find I turn to them for that reason after the Hornady gauge (mine's actually Stoney Point, from before Stoney Point sold the gauge design to Hornady) has given me base numbers. It's just that I usually need to average several measurements with the calipers before I fully trust what I'm getting. Once I establish that, I use the PM to double check what my seating die is putting out.