Hi there, thanks very much for an informative post. I am replacing the main spring on an Original Model 50 and have followed your instructions. Everything seemed to go fine as you outlined. However, after putting it all back together again - the gun will not cock. The cocking lever goes all the way to the rear, but the action is not held at cock. I do not really understand the way the ball bearing sear works so would be grateful for any information that. If you have any pointers for what else to look for I would be grateful