I’ve always left powder in my throwers…. I recently “upgraded” to a new manufactured Lyman 55. Left Titegroup in the hopper about a month and it “shrunk” and no longer seals to the body.
Is this an issue with the powder, or the hopper? It’s never been an issue with other powders, but in all fairness, I just started using Titegroup at about the same time as I got this measure.
FWIW, it hasn’t affected my Dillon 650 hopper