No offense Bushmaster, but it sounds like you aren't maintaining your equipment in the most studious manner possible. If your powder measure fails to dispense a charge, under any circumstance, it should be replaced or repaired because it is defective. It is an error to keep using a device which you know to be defective under certain circumstances and trying to blame it for your lack of will to repair or replace it. If your tools, which you make a living with, are don't work 100% of the time, you replace them, right? Why would your powder measure be any different?
As I said, unless the device has a catastrophic failure, i.e. it does not dispense a charge, then only the operator can be blamed and when the operator knows the device is defective and continues to use it, he is doubly to blame. That is like saying, "Well the aircraft engine normally works but sometimes it just craps out but I'm just going to check it more often rather than fix it." The right thing to do is fix the root cause or replace that engine. Inanimate objects don't make mistakes, people operating/maintaining them do.
I agree that checking to make sure a load is dropped everytime is a good thing to do, that is how you catch a problem with your equipment. I never said that devices don't fail, they do. However, blaming the powder measure for not dispensing a charge is shifting the blame from where it belongs. I stand behind my original assertation that an inanimate object like a powder measure, excepting failures, cannot be blamed for no charge/ double charges.