Boiling this down some more....
The OP was not about "what kind of gun do you like". It was about examining the
requirements for a self defense firearm, and using that analysis to narrow don the list of firearms from which to choose.
In an effort to keep from becoming too "inside baseball" in terms of a structured requirements analysis process, I was just a bit informal, and I skipped some steps.
What I did was establish as requirements some that were really derived, lower tier requirements, without actually having shown how to derive them from true primary requirements.
We should start at the top and work down. We do not start with "I need a Glock", unless we already know that we intend to acquire a gun that operates exactly like the Glock that we already have.
Let's try it from the top, just to illustrate the process.
Perhaps we can agree on the following as primary requirements:
- The firearm must be effective for real world self defense.
- It must be concealable.
- If must be something that one can and will carry all the time.
- It must accommodate the physical abilities and limitations of the defender.
That should be about it. Everything else, I think, can be derived from those.
Let's start with the first one and work down from there.
To be reasonably effective for self defense, a firearm for primary carry must ...
- ...provide adequate terminal ballistics--penetration, etc. (one might equate that to "the performance of it and its ammunition must at least approximate FBI testing protocols).
- It must facilitate fast shooting with combat accuracy--a balance of speed and precision (that will get into recoil, and thus into caliber maxima. size and weight minima, and into rigger pull, grip size, etc).
- It must have enough capacity without a tactical reload (that will be subject to judgement).
- It must be reliable.
- It must be able to be readily brought into action very quickly, without unnecessary delays.
When we think about those, we should be able to eliminate from consideration quite a number of handguns, but it will not lead us to an obvious choice. For that, we have to consider the other primary requirements--and do some shooting.
In the OP, I listed as one of my requirements a rather 9mm semi-auto with a certain desired ammunition capacity. But those were really
derived requirements, that stemmed from the first three in the second set above.
The bit about the separate safety derives from the fourth and fifth items.
To illustrate further, the first and fifth items would eliminate Bat Masterson's ten shot Savage .32ACP, which incidentally, I like a lot.
I hope this helps get the idea across.
Now, let's go to the second requirement--concealment.
There is no "one size fits all". what one person may be able to conceal, in his or her attire, will obviously doffer from that of another. It's an an individual thing.
The same thing applies to some extent to what one may want to carry all day.
These requirements will probably eliminate an eight-shot N-Frame revolver from consideration for just about everyone, but after that, it's an individual manner.
To the extent that this indicates a smaller or lighter firearm, we may have to compromise on some of the performance factors.
The last requirement--taking into account the physical capabilities and limitations of the carrier--may be a simple as choosing a pistol that requires less effort to rack the slide, or it may affect the choice of grip. Or it may have to do with recoil tolerance, and require cartridges with less effectiveness.
Now, since we are not defining requirements to submit to a manufacturer, what we have done is shorten the list of acceptable off-the-shelf items. We are not yet at the point of saying "the requirement is for a particular Glock in 9MM".
To get there, or to a SIG or Springfield or Ruger, we have to do some shooting, and if at all possible, try a firearm in a defensive pistol class.
I hope people find this useful.
Full disclosure--when I started carrying concealed a more than a decade ago, my understanding of defensive shooting was insufficient to support the successful conduct of the process described above.
As a result, stores made a number of sales of firearms and holsters that I did not really need.