I believe there is an issue with the hammer making contact with the firing pin in half-cock. I have been using a Ciener for about 3 years now, and just passed the 10,000 round mark. I never use it in a manner that would violate the known safety issue, and it can be ammunition sensitive (I stay away from the 36 gr hollowpoint stuff). Other than that, I am a big fan of the system and can't recommend it highly enough. Edited to add: I use my Ciener on a parkerized SA Loaded model.