Single Actions were mostly early design, but replica’s are still made today, and there are probably some new ones as well. Not real practical for personal defense, but definitely still popular with the cowboy action shooters. For most purposes other than cowboy action, if you are carrying a when gun, it will be double action. You can fire a double action as a single action simply by cocking the hammer yourself. Thats recommended when you are learning and for accuracy. But for safety and when you need to shoot now, double action works just fine. :)
Your knowledge is encyclopedic. Thanks again!
I never could fire accurately with a double action. I always cock the hammer back and then fire. Doing it that way I can hit a target decently. Trying to do it double action, it just never goes right.