The key to peace and harmony on this subject is to accept IMPERFECTION in our terms. We use terminology in our hobby that isn't always "exactly right" for one reason or another, but we've dragged many of our terms along across decades or more.
We know that "single action" means the trigger does only a single job (drop the hammer) but in actuality, it does more than that in most handguns. In the subject 469, it also defeats the firing pin lock.
Back in the 1980's when the Glock blew up in popularity, they had to think up a NEW term for the trigger/fire control system. At first they called it "safe action" and eventually they christened it "striker fired." But where the rubber meets the road, the Glock trigger (and most Tupperware guns) takes an already half-cocked (or pre-tensioned) spring-loaded firing pin and it draws it further rearward and releases it. Which is AWFULLY similar to the ages-old "double action."
With most striker fire Tupperware, the trigger first defeats a dingus that would otherwise prevent trigger travel, it then adds more energy to a striker, it then defeats a firing pin lock, and ultimately releases the striker, allowing the pistol to fire. And in a classic double actuon revolver, the trigger does even more, advancing a cylinder, locking out a cylinder release, adding potential energy to a hammer, locking a cylinder from rotation, moving a hammer block or transfer bar, and finally... releasing a hammer in hopes of firing a round.
Double action?! Maybe we should re-name it to PolyAction!
Or better yet... know going in that our terminology is far from perfect but typically, it works. Much like we all know that .38's aren't 0.38" but these days, we don't fret over it. Much.
