One of the things you can do if it leaks....take off the hopper, and tape the disk to the aluminum base tight so it is flat against the bottom. Tape it so that the tape runs from front to back on the base, the same direction the disk moves when you drop a charge, not over the two wings on the side that the screws/nuts go through. Now, flip the whole thing over and lay the top of the wings flat against some 600 grit wet/dry sandpaper on a pane of glass. Now gently push the base back and forth on the paper, reducing the height of the "wings" until you just start to sand on the tape running over the center of the disk. Stop, reattach hopper and notice how it more snugly tightens down on the disk.
If those wings are just a little too tall, then the wiper on the bottom of the hopper can't "seal" against the moving disk enough to keep fine-grain powders from leaking.
That said, H-110 still leaks a little in mine. Not enough to change the charge weight, but enough to require cleanup. But, I don't know of many powder measures that won't leak H-110 unless they are dead nuts perfect tolerance-wise.
