I was loading 204 Ruger last night and had set up my Jones Precision measure to drop 25.5 grains of IMR 4064. It was dropping charge after charge with unerring accuracy -less than a tenth of a grain measured on my Ohaus Dial-o-Grain scale. I installed the small diameter drop tube and began charging cases -handing each case off to my lady friend to rack in a separate loading block. When I was done, I took my trusty flashlight and visually inspected the charge in each case. What do you know! Many of the cases had charges visibly less than others. One case had only 20.8 grains. I concluded that the powder was partially bridging at the head of the small-bore drop tube and caused varying amounts of powder to be dropped into the case at each toss of the handle.
As I was dumping the powder back into the bottle I remembered Dutch Henchie, the man who would tap me on the back of my young head with his old EverReady Captain flashlight (torch, to you) and tell me to "Check every case! One by one!" when showing me how to load for the 30-40 Krag-Jorgensen. A good lesson learned.~Muir