I've been using a G.P.S gauge ($21) and it seems accurate but hard to read, so I splurged and bought the Lyman gauge which is $57. It is certainly easy to read and seems consistent, but consistently *wrong*. Weights read about 1 1/4 higher on the Lyman than the G.P.S. Based on a number of things, I think the G.P.S is giving correct readings.
I've now ordered an RCBS gauge to be a tie-breaker, but I'm wondering if anyone else out their has encountered inaccurate Lyman gauges.
