What is a double action pistol?

Answer 1

A single action pistol, such as the 191A1 .45 Auto, requires that the hammer be cocked before the first shot. A Double Action pistol does not need to have the hammer cocked- pulling the trigger causes the hammer to rise and fall. Some are DAO- Double Action Only- the hammer cannot BE cocked, and must be fired from a "hammer down" position. These include the Para-Ordnance LDA pistols.