To the best of my knowledge, which is limited, and certainly when it comes to action work, I was of the understanding that the thumbpiece is an external part, a tool so to speak, used only to actuate the bolt in order to open the cylinder. Mention has been made above that some modification to that part can enhance the trigger pull, or action in some way.
Can someone clarify this for me? Id like to learn about how that works and exactly what is the necessary thumbpiece modification that makes it do that job. I'm not disagreeing.. just not familiar. Thanks for the help!