I recently had an argument with a buddy of mine over what kind of action a Glock had. I refused to defer to my friend's wisdom, because his argument that Glock pistols were DAO (double action only) didn't seem right to me; after all, you can't just keep activating the firing pin by pulling the trigger. You have to literally pull the slide back every time, which to me sounds like a single action system, as evidenced by the "SA" marking on the Glock's counterpart, the Springfield XD.
It turned out that we were both sort of right; striker fire pistols like the Glock are a bit of both. Although they are single aspect in the respect that the firing mechanism can't be activated without essentially "cocking" the pistol by pulling back on the slide, the trigger system can also be considered double action.
Four pistols lined up for this discussion, including the one on the far right, which is a pre-WWII pistol that used the Striker-fired design.
On the Glock platform, the firing pin is considered to be half cocked when the slide is retracted and a round chambered. As the shooter pulls the trigger back, the firing pin is simultaneously being cocked, very similar to a double action design.
The Springfield XD series, unlike other striker-fired pistols in the market, has a protrusion at the rear of the slide to indicate the firing pin's cocked position.
So, now that the argument is over, and we both learned a little, we also learned that the common misconception that the striker-fire system used by the above pistols is fairly new is complete rubbish, as evidenced by a few pistols that have aged more than 75 years.
An Ortgies handgun chambered in .32 ACP. For literature-freaks, this is the same gun mentioned in J.D. Salinger's "A Perfect Day for Bananafish".
The Ortgies is a post World War One handgun made in Germany. The pistol uses the striker fire technology similar to those of our modern day Glock and Springfield pistols, suggesting the hammerless striker-fired system is quite antiquated but still works just as well.
