Thanks, JS, interesting idea. I sure like the Magguts +1 that doesn't extend mag length, though. If Shield mags are thicker, as GerSan69 seems to suggest, maybe there is some other Magguts kit that would work on a CS9. I sold my Shield so can't compare mags easily. Maybe I just need to order one of every Magguts kit at $23 each and see if any work. I would have thought someone would have performed this experiment already.