I better get busy. I don't think I've shot 10k since I started shooting period. I did get a late start though.
I read an email from HK customer service that a guy posted on another forum. He had emailed them asking when they recommend changing the spring, specifically if it should be every 3k rounds. They responded that there is no set count for change-out, but that they recommend it be sent in to be looked at by their armorer every 10k rounds. I imagine shipping would be on your dime, though.
Thanks for Sharing this info OPs - Tricks 9.
Sounds easy to do and good maintenance!