Hi
T/C has made several hammers. All of them have the ability to shoot rim fire and center fire. The earlier ones you need to use a screw driver on the front face of the hammer, and flip the little striker thingy. Half of it sticks out a little farther then the other half. If you have the protruding part up, it is rim fire, and down is center fire.
Newer hammers have a switch on the top of the hammer. You can move it around, and watch the hammer face there is a little pin sticking out. If it is up , rim fire, and if it is down center fire. Maybe in the middle of switching it around is the safety. I hate to admit it but I don't use the safety. If it is loaded and closed I'm going to shoot, otherwise it is empty and open. If some one wants me to stop I open the frame...Safe.
Hope this helps
jim