The Lee Perfect Powder Measure is, alas, not perfect. However, after reading this post, you can make yours perfect.
Start with this:
Use my fingers and your imagination, as well as your knowledge of the dimensions of your average ppm for sizing, cause I cant remember off the top of my head what the numbers are. I found this piece at work, but you could probably make something similar with a tupperware tub or something. when you see the finished product possibilities will leap to the imagination. I am sure.
Anyhoo, take your piece of plastic and drill a 3/16 hole FROM THE INSIDE. It should look like this:
Next, take the appropriate size hole saw, stick the pilot bit into the hole previously drilled, from the outside this time, and drill out something that looks like this when you done.
Make sure you got a really good grip on the plastic or have it clamped down. the hole saw WILL grab and will try to wack you in the nuts. I know this for a fact.
Now you want to trim off the two rounded edges a bit so that the powder hopper doesnt get completely blocked off by our now nearly finished baffle. It should look like this when you done and polished off all the burs and stuff.
Now put a piece of scotch tape over the hole in the center and we are ready for installation. Now drop it into your Lee PPM pointy side up. You are done. You now have a truely perfect Lee Perfect Powder Measure. Now it will not only throw perfect charges, it will throw perfect charges no matter how much powder is in the hopper.
You are welcome.