This needs a learning curve to be 90% good. The way you hold the good is important and ease the primers to gently slide to the exit hole. Move the primers to be in line and not on several layers which may create a jam.
The primer which reaches the exit hole may go nearly upside down and needs to be manually set properly. So, I have drilled a small hole just above the hole to introduce a needle to do that. Otherwise, this product is much more efficient than the 100% manual picking and has 1 to 2% upside down position.