I had been for waiting for Magguts for my CM9 mags for several months and received notifications that both the 7-round spring for the 6 round magazine and the 8-round spring for the 7 round magazines.
https://magguts.com/product-category/kahr/
I bought two of each and just tested them last night without any problems. They are very hard to get that last round in the first time you load them, so I would use a mag loader to help.