The Mcdonalds straw approach minimizes the clumping that the factory threaded tube allows to happen. Without the straw, the unit will drop too many grains of powder when it is in trickle mode and cause overthrows. Also, have you adjusted the settings......If you do a google search on "chargemaster settings" you will find numerous pieces of information. I have mine fine tuned to maximize speed and I only see a couple of overthrows per 50 loads. The Chargemaster is the single biggest improvement I've found in reloading.
