Outbackandy: I am certainly happy you were NOT injured!
My friend was using his Lee handpriming tool to re-prime about 500 45 ACP cases while he and his wife and two daughters were watching T.V. one evening a few years ago.
At a tense moment in the movie they were watching his priming tool "lit one off"!
I guess it was really loud and in the confines of their T.V. room.
There were screaming crying girls running in every direction for a while - and again luckily no one was injured.
I have been reloading centerfire Rifle cartridges since I taught myself to do so when I was 12 years old - I am now 69 and I have never had a primer detonate on me as I was installing them (a couple hundred thousand rounds?)!
No, you are not the first, but I tend to think your incident did NOT need to happen.
NO slamming nothing, when I am reloading.
Hold into the wind
VarmintGuy
