I have been using this measure successfully for many years. But in the last month there were 2 occasions where the hopper became loose while I was charging cases. Gunpowder spilled all over the bench and floor and was a mess to clean up. The hopper just looks like it is pressed into place in the assembly. I have pushed it in as hard as possible on both occasions but in several weeks it came loose again. As far as technique is concerned, I am not doing anything different than I have been doing for the last 50 years. I would appreciate any suggestions as to how to correct this . TIA