I have the same setup G27 with 9mm storm lake conversion and G26 mags. I use it for practice and a few competitions also. Never had a hiccup but just prefer to carry with .40 for the extra stopping power.
Originally Posted by JimM_PA
My G27 with Storm Lake 40-9 conversion barrel and G26 mags has been reliable so far in several IDPA club matches. However, the search feature is your friend and should reveal a number of issues other shooters have experienced from time to time (extraction, ejection, etc.). The conversion barrel is a compromise and meets my intended purpose, but I prefer the G27 for carry.