my insert inside the powder tube that guides the powder into the shell casing gets stuck sometimes on my pro 7 press,this causes some of the grains of powder to fall out onto the shell plate. i ve polished the aluminum adapter with fine Emory cloth and fine steel wool. even cleaned the inside of the tube with a bore brush and solvent and then ran a clean cloth thru it. it work for a couple hundred rounds and then it happens again any tricks of the trade to prevent this .i can see no nicks or rough edges on the adapter the powder is imr 4198