Maybe it's just as well that even people with CCWs often leave their firearms at home. Why? Well...
Long story concerning people in training simulators. Skip to "LGS Story" if this is too long!
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I've had opportunities to observe a number of CCW holders go through our local PD's decision simulator. Even with fairly simple shoot/don't-shoot scenarios, their decision processes would best be labeled "utterly clueless" and their marksmanship was equally as bad. And these people had at least enough "expertise" to pass the easy practical part of NC's required coursework.
One of the scenarios in the simulator: "CCW" exits building into parking lot, hears shouting. Sees two men trading punches, with a woman looking on and waving her arms and shouting. "One" man quickly begins to get the better of "other," whereupon "other" drops back and pulls a pistol, pointing it at "one," yelling 'stop.'
First guy playing part of "CCW" has pulled his pistol and shoots "other," instantly stopping the scenario.
The instructor calls me up. The scenario starts again... when "other" pulls his pistol, he immediately shoots "one" and instantly turns his pistol toward the woman. I light up his A-zone. Scenario stops.
Instructor plays both scenarios again, without "CCW" taking any action.
- In first guy's scenario,"other" keeps retreating with his pistol on "one," yelling "stop!" and "one" quickly departs the area, whereupon "other" holsters his weapon and yells "somebody call 911!" Instructor says to first guy, "You just killed the good guy and you're probably going to prison. At the very least, you're looking at tens of thousands in legal fees."
- In my scenario, ""other" shoots "one," then the woman, then "CCW." Instructor asks me, "Why didn't you fire as soon as you saw that "other" had a gun? You might have saved "one." I said, "I didn't know which guy was the aggressor - but when he instantly shot "one" and turned the gun toward the woman, I fired." Instructor said, "You have a reasonable defense."
From a statistics perspective, CCW holders are extremely unlikely to cause trouble with guns. That doesn't make them competent in deadly-force-decision scenarios. I've had a little training, enough to heed the mantra that came from the most hardcore instructor I ever had: "A good run is better than a good fight" (paired with "Buying a gun and thinking you're armed is like buying a guitar and thinking you're a musician").
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LGS story: Young woman comes into a beginner-level class (taught by aforementioned hardcore instructor) whose pre-class prep material specifically said to bring 250 rounds of ammo (this was years ago when 9mm ball was ~$8 per 50). LGS had sold her a subcompact S&W 9mm as her first-ever pistol. By the end of the first exercise - less than 20 rounds fired - the woman was unable to put rounds on a person-size/shape target at ten feet, and the palm of her strong hand was raw with traces of blood showing. Instructor, as kindly as I ever heard him speak, asked her where she got the pistol and why she picked that one. "Where" was an LGS that actually had some knowledgeable people. "Why" was solely because she liked the size and the LGS asshole was happy to ring it up for her.
Everyone kindly tried to persuade her to buy a .22 or at least a far less "snappy" pistol with which to learn. I used to have a positive attitude toward that store, but it ended that day.