If you stay in Production division, the first shot has to be double action.
https://uspsa.org/documents/rules/20...tion_Rules.pdf
"Special conditions:
1. Only Double Action, Double Action/Single Action, and Safe Action/Striker Fired handguns are allowed, and must be on the approved list.
When in the ready conditions as specified under 8.1, a gun with an external hammer must be hammer down. A hammer is considered to be in the "hammer down" position when the hammer is placed there by pulling the trigger while manually lowering the hammer (manually decocking) or by activating the decocking lever if present. Manually decocking to the half-cocked position is not allowed and will result in the competitor being moved to Open division."