I might only add, If you do have a TC lock, and it does have a screw on the tumbler? It’s been modified to replicate CVA’s or older Russ Hamm lock tumbler’s.
Also, never seen an allen head screw used before either?
Lastly, If you screw in, you push the sear nose out of the full cock notch towards the notches edge, thus reducing area space that the nose of the sear rests on when the lock is fully cocked. This creates a lighter pull needed using your firing trigger to trip the sear nose free of the tumbler notch, thus firing your rifle.
To adjust this screw, I visually observe how much of the sear nose is resting in the full cock notch of the tumbler. If your firing trigger pull is to heavy you turn a quarter of a turn to half turn inbound. Again check the sear nose/tumbler contact. Definitely don’t want the edge of the nose resting on the edge of the tumbler notch!
After you adjusted and are happy with your lightened trigger pull, go ahead and push on the back of the hammer with your thumb forcefully with the lock fully cocked? If the hammer falls, you need to back off that screw! Repeat process until you can’t drop the hammer using thumb pressure. Take some finger nail polish and dab on the screw to prevent it from working loose.
Respectfully, Cowboy