I have noted different brands of 9mm fall out of moon clip. I typically purchase 9mm ammo for semi auto and consider clean burning powder as my preference. I am a little disappointed that now I need to consider "revolver" 9mm ammo for moon clip retention.
I've used TK's moon clips for years, first for my Ruger GP100 10mm and now for my S&W 610. They always worked perfectly and I have never had an issue with bending or becoming unusable. Well worth the price.