I have the same pistol in 50 cal. and it does the same thing. I was at the range with it and was talking to a gunsmith that was finishing up work tuning a rifle he was working on, about what I thought was a problem. He told me that was supposed to work that way. It's a de-cocking function, so you didn't have to fully cock the pistol and pull the trigger to let the hammer down. I don't think it's a mechanical malfunction. make sure to pull the hammer all the way back, you'll hear 3 clicks, first is half cock, second click is the de cocking function, and third click is full cock. I know it doesn't seem right but since we have the same model and same function??