A few years ago I read on this forum about a pin coming loose I think on only one end, I forgot who it was though.
I understand what you are saying Andrew. I'll try and remember to get in touch with the customer next time we come across a piston like this. I think I've only seen 2 in the year I've been here though, so it won't be any time soon.
Maybe I can try and simulate it on the test bench...
Intentionally trying to destroy a dynamic advance piston...sounds like fun... 
Tyler's living the dream... and I mean it. Getting paid to mess with diesels... that's like getting paid for having.... never mind.
It's not all fun and games
I can't wait until I know more stuff and can build my own custom pumps