Several approaches. One is to work on the hand, teh other is to work on the Bolt/cam interface.
1) Check the hand to see if it has a burr on the tip, this could be the culprit. The hand may also be shortened slightly.
2) Alternately you can remove a small amount of material from either the bolt (cylinder stop) in the hook area (contacts the hammer cam), or remove a bit of material from the hammer cam. On some revolvers the cam is an assembled component to the hammer. If this is the case, you can rotate it a bit.
I recommend extreme care & caution when performing this work.....too much removal can cause the timing to shift the other way.
If it were a 3rd Model Dragoon, I'd have simply suggested you sell it to me

Regards & good luck