✔ 最佳答案
With a SINGLE action Pistol OR Revolver, one MUST manually pull (cock) the hammer back to firing position before pulling the trigger.
DOUBLE action means that you can fire the weapon starting with the hammer down by JUST a pull of the trigger (although usually with a much harder pull)
The 1911 pistol is SINGLE ACTION because you MUST manually cock the hammer before you can fire the first shot. After the first shot, the slide pulls the hammer back for subsequent shots, but it's STILL a single action pistol.