LOL it was bound to happen eventually.
The eternal quest of the hand loader. How much powder can I put in that case. How much lead can I put in front of the powder with out the whole damn thing blowing up and how far and how fast will it go, accurately of course. Might I be so bold as to suggest they forgot the part about accuracy and how far.
It reminds me of my youth. In 1961 (I am old now) I was doing a bit of experimenting with acetylene. I figured out how to make it and then decided to burn some. Unfortunately due to my ineptness I allowed some air to get in the mixture. It did not burn, it exploded along with the glass container it was in. My grandmother came running out of the house to where I was. I had numerous small scratches and cuts on my arms but nothing to my face and eyes. She asked what happened. I answered 100% truthfully, "I think I made a mistake."
She did not know about the nitroglycerin that I had made and keep in the freezer. I disposed of it post haste.
My best friend in high school was the son of a chemist. His dad was a great guy. Unfortunately he gave us unsupervised access to his lab. It is a damn miracle that we did not blow up both our houses.