Does anyone know which hi cap magazines fit the ruger .40cal carbine and the marlin camp carbine 9mm. ?

The Ruger takes Ruger .40 cal mags, so you are pretty limited to anything "high" capacity (11 rounds is factory).  Some outfits make junk mags that are 20 rounds or so.  I wouldn't even bother with those.  The Camp 9 takes S&W 59 mags.  You can get factory 20 rounders, and Mec-Gar 20 rounders for it, both of which are quality.  So..........if you really want reliable high capacity, go with the Camp 9, or a Ruger PC9 as you can get 20 round Mec-Gar mags, plus 15 round factory.    

thanks