Lots of handloaders under no circumstances heard about “seasoning” a different powder measure by operating a pound or so of powder via it. The speculation would be that the graphite coating on the powder granules (and inside the dust at The underside of a can of powder) comes off somewhat https://dominickomida.weblogco.com/35580320/hodgdon-blc2-smokeless-gun-powder-now-instock-an-overview