One mistake that I made about seven years ago was let my young son 14 at the time was to use my equpiment unsupervised. He helped me quite a few times in our basement and in his defense he was a safe kid. I own a Dillion square deal B which is a four stage progressive reloader. For those who don't know it is that after you start loading after the first four rounds, you got all the stations going, you get a loaded round every crank of the handle. I have never had any trouble with my reloader and every thing comes out right on the money.The machine was all set and ready to go,by me,the night before. I only had three pickup tubes ready to go. Thats what holds the primers to load into the main tube, you load the pick up tubes yourself. Anyway my son ran out of primers and took it upon himself to load up a few more tubes. Luckily I came home and went down to the basement while he was on his first tube of fifty. When he loaded the pickup tubes he loaded the primers into them upside down. He had about thirty rounds loaded with the primers fully seated upside down. He said the handle was just a little harder to pull down but didn't give it any thought.Luckily none of them went off and we had another lesson for him to learn. So whether you are only loading a few rounds at a time or able to crank out 600 + an hour take the time to check out whats going on with your ammo instead of waiting till your done and do your final inspection. Could save you a serious injury or death to you or someone you love.