Jim, this is not an uncommon question...
Jim, this is not an uncommon question...
With today's plethora of choices in action types it can be quite confusing, I'll try to shed some light on it for you. As you already are familiar with the 1911 and Ruger it won't be as hard as understanding CLT vs HTL!
In handguns there are two basic types of actions, Single action and Double action. This applies to revolvers AND semi auto's a cheap and easy way to tell when looking at the gun is if you can fit your finger in the space BEHIND the trigger it is a double action (rule of thumb) if not think Single action. The difference being that a single action when the trigger is pulled only performs a "single" action ie the hammer falls (think old west cowboy revolver) If it isn't already cocked the hammer doesn't move. Now in a Double action (think Smith and Wesson) if you cock the hammer the trigger moves backwards in the trigger guard and now is in the single action mode. If you don't cock it first but pull on the trigger all the way it will now pull the hammer back for you and THEN release it (two actions) or double action. This is lengthy but you'll see why shortly. So with our understanding of the difference between single and double action where would you classify a small revolver that has NO EXPOSED hammer? (they do have a hammer its just internal) The name the industry came up with is DAO or Double Action Only which of course is an oxymoron but it suits the fact that you can't cock it manually. NOW on the semi auto pistols side you have the same choices, the 1911 is a Single action auto, if you don't first cock the hammer the trigger does nothing, the hitch here is that the hammer is usually cocked for you when you load the chamber by racking the slide to the rear, so some people forget that they are cocking the gun. Along the way many people came up with double action triggers for pistols but the books and most semi knowledgeable gun guys will point to the Walther series of pistols as the first commercially successful "Double action pistol" which it was claimed would be better for cops holding a suspect at bay because the first pull of the trigger is very long and heavy, but after the round cycles the slide it cocks the exposed hammer FOR you thereby giving you a light easy trigger pull for each successive shot (like your Ruger) this was great marketing but really more a discovery/evolution than design I mean really what else was it gonna do? the first three in double? the gun doesn't work that way, but much hype was placed on Walthers feet for this design, but there is one HUGE drawback that people seemed to be forgetting, the transition from LOOOng heavy pull for the first shot to light and easy was damn hard to master under stress. With the first shot mostly being thrown into the ground while waiting for the gun to cock the hammer (interesting side not here, MOST double action autos have a decocker to let the hammer go from cocked single to uncocked double action mode. The CZ-75 series is a hybrid with a safety that allows the gun to be carried in either single cocked and locked mode OR double action mode at the flick of a switch)...Jim...wake up Jim...stay with me here, OK so with the double action being safe but hard to control and the single very easy to shoot with but not as safe for pointing at people you might not want to shoot, the manufacturers began to look for a solution to both problems, enter the Striker fired pistol and again most people point at the Glock and go OOOhhhh but they weren't the first (in anything). The HK VPZ-70 was the first practical Striker fired gun where in the trigger actually pulls back the firing pin to a set distance and then releases it to strike the primer (how many actions was that?) Problem was the HK was as usual a poorly designed P.O.S that was a cross between a machine pistol and a spatula. the trigger pull was about 25 pounds (no s#*t!) and the gun was un-useable. But the idea was born, Next came the Rogak or Steyer (I won't argue which was first) where they tried to improve on the idea by pre staging the striker (firing pin) when you racked the slide (sorta like cocking the gun but no hammer) Problem with this system is if you have a round go "click" when it should have gone "BANG" you now have to cycle the slide again ejecting your dud round in the process to get a fresh one in the chamber and pre-stage the striker again (today's training exemplifies this). This is how ALMOST all Gocks, XD's M&P's and their ilk work. The exception to the rule is the Taurus line of Striker fired guns who have "Repeat strike capability" or in other words you can pull the trigger twice. The main benefit to Striker fired guns is that the trigger pull is always the same and not too bad on some. As for the Taurus a nice side benefit is during dry fire practice you get the same pull without having to rack the slide in between.
Jim, I realize this was WAY longer than anyone wanted to read and after re-reading it it will probably lose some without a gun in front of you to look at. I am happy to answer any questions you might have and will TRY to be less confusing.
Hope this helps
Ben S (stayed in a Holiday Inn Express last week!)