OKFC05, thanks, I've checked the "push off" and it's not going anywhere. Reading the Model 19 thread going round, I also checked the mainspring screw and it's tight. I suspect I've simply got a well worn lady that I'll have to be careful with if I ever shoot it in single action. For the record, the only time I ever shoot a double action revolver in single mode to for checking the sights and/or aim. My training was always in double action, that's where I sit today, an extremely poor shooting double action guy!