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Old January 17, 2013, 11:53 PM   #1
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One reason why we need more than 10 rounds...

One of the questions I'm hearing frequently is antis asking why anyone needs high-capacity magazines.

Awhile back I did some thinking about multiple assailants and what happens when one factors in the likelihood that misses are probable in a real-world shooting. I decided to run the probabilities. The results were eye-opening. Maybe some of the results will be useful.

You have to assume a hit rate and I used 30% for the initial scenario since it is a fairly representative hit rate for LEOs in gunfights. Most experts will tell you that it's a good idea to plan that it will take at least 2 solid hits to properly pacify a determined aggressor, so I set the scenario up to require 2 hits per assailant.

In a scenario with 2 attackers and an assumed hit-rate of 30%, 10 rounds gives the defender about a 35% chance of making 2 hits on 2 opponents before the gun runs dry.

In the same scenario, same number of attackers, same hit rate, 15 rounds give the defender about a 70% chance of making 2 hits on 2 opponents before the gun runs dry.

The extra 5 rounds change the scenario from one where the defender fails nearly 2/3rds of the time to one where the defender succeeds almost 3/4ths of the time.

There are some other assumptions inherent in trying to apply these probabilities practically. For one thing, it assumes that the defender is able to tell how many hits have been made on the first assailant and then immediately switch to shooting at the second assailant after making 2 hits on the first--wasting no additional shots on an already neutralized opponent.

The assumption is made that the defender is able to empty his/her weapon in the course of the gunfight--he/she is not incapacitated before that can take place.

The assumption is made that 2 hits disable the attacker, and further that the attackers keep attacking until disabled. Obviously, sometimes attackers run away in the real world.

In effect, the math assumes a sort of best case scenario. In other words, with a hit rate of 30% the defender might do worse than the numbers suggest, but it's pretty unlikely that they would do better if both attackers don't give up until they're disabled by 2 hits.

Here's the original thread.
Did you know that there is a TEXAS State Rifle Association?
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Old January 18, 2013, 12:08 AM   #2
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Yes, I was explaining the exact scenario to someone the other day. It seems as if some folks think guns are magic and each bullet hits the mark and immediately stops the threat. I tried to explain that a lot of shots miss in a real life situation and it often takes several to actually end the threat.

Although I do remember you posting that data I had forgotten about it, so thanks for the reminder.
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Old January 18, 2013, 12:13 AM   #3
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Ferrel Hogs

Ferrel hogs. You need either 1 round or 50+
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Old January 18, 2013, 12:22 AM   #4
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Doesn't the FBI say hit ratio of LEO is 14% ?

Anyways, if you are a deer hunter, you know one shot may be one kill, but a shot through the heart and both lungs - the deer still can run almost 100 yards, and that is with a high powered rifle using expanding bullets.

What's the percentage of bad guys getting shot and still live? It may be higher than dying.

A bad guy with a gun may need 30 rounds to stop him if he keeps attacking. He may flee after getting hit, but he might not. Each situation is different, that is why you carry as many rounds as the potential exists.
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Old January 18, 2013, 12:53 AM   #5
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5 guys kicked their way through my front door one morning around 5am

If they had been determined to hurt us, I would have wanted far more than 10 rounds to deal with the threat of 5 people.

I was lucky that they realized they had kicked their way into the wrong house, they wanted the people next door and backed out once I informed them of what they had done. If I had been armed at the time there would have been a lot less yelling and a whole lot more of a dead guy or several in our house. Mistake or not, you get whatever you meet on the other side of a door you kick in.
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Old January 18, 2013, 01:30 AM   #6
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This same conversation has been heard often by me! The answer to the 6/7/8 or 10, is enough rounds for a gun fight? Is this, what if it is not?

So I find 16 rounds of 9mm Ranger T, 147g jacketed hollow points, at 1000 fps, is kind of OK.

If not, the Glock 17 spare magazine will have to be added to the disaster!

A common mistake in Home Invasions, "The wrong house!"

So 5 male druggies, in your front door, bits of wood every where? Nice to be able to lob a bunch of rounds into them, it is called positive reinforcement?
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Old January 18, 2013, 01:30 AM   #7
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I always love hearing scenarios such as these.

I'm actually worried that the mob will come after me or send professional assassins. If this is the case, I'm not a very good shot and would require atleast a mini-gun to properly deal with the situation.

I'd also like to own some type of chemical gas incase I get trapped in the bathroom and have no ammo but only my chemical resistant gear.. What is happening to this country that we can't protect ourselves!
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Old January 18, 2013, 02:00 AM   #8
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the anti think real life is hollywood and one shot means the BG is dead or unable to function. Anti's are ingornat.
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Old January 18, 2013, 09:00 AM   #9
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Remember the early Cowboy pictures, quick draw, chrome 45, one shot from the hip! the bad guy topples off his horse!

We played Cowboys and Indians? Never caused mass shooters to emerge, not on my street.
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Old January 18, 2013, 10:37 AM   #10
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Round capacity is a legitimate concern. Good example is the Trolley Sqauer Mall shooting in Salt Lake City.

The off-duty officer who initially engaged the shooter, Ken Hammond, was carrying a compact Kimber single stack 1911. His pistol held 8 rounds (7+1) and he wasn't carrying a reload.

Originally Posted by PoliceOne
He now had a clear line of vision to the gunman and fired at him. Due to pending investigation, Ken cannot disclose how many rounds he fired, but he did share that his limited cache of ammo was a point of concern.
If it's a concern for an off-duty officer out of his own jurisdiction, why is it any less a legitimate concern for the rest of us?
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Old January 18, 2013, 10:41 AM   #11
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The OP has an eye opening theory. It makes a lot of sense.
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Old January 18, 2013, 11:08 AM   #12
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Guys, do not try to rationalize with the anti-gunners. They will take every inch you give and then take another foot. they will find a way to twist every statement or fact you offer.

Don't reason with them and try to justify it with irrelevant issues like hunting, target shooting, or anything else.

The reason is simple. The 2nd amendment exists so that we possess the ability to fight for our freedoms if the need arises. And we are allowed weaponry with the ability to do so.

When they develop Hand-Phasers I want one of those too
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Old January 18, 2013, 11:37 AM   #13
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I agree that the O/P is well reasoned. Urban areas especially compel the conclusion that more is better.
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Old January 18, 2013, 12:27 PM   #14
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I wish I'd saved a link at the time. I was in Pasadena for work the week after Thanksgiving and on the Monday evening I arrived the news was all a-twitter about 3 bodies found in an Ontario, CA house.
On Tuesday AM, there were a few more details and 1 suspect in custody. Apparently, there was a home invasion by 3 people. The homeowner was armed and the police found the homeowner and 2 perps dead.

B/c I often think about things like capacity and home defense, several thoughts occurred to me in a particular order:
1. TV says "neighbors heard gunfire in the house on Friday night." And I think "and no one called 911? You need new neighbors."
Lesson learned: Maybe you can't reach the phone. Don't expect someone else to call 911. Don't expect that the cavalry is coming.

Then I remembered the stats quoted in your original thread about how poorly police shooting is during real shoot outs and the fact that Californians are only allowed 10 round magazines.
2. The guestimate math: 3 attackers times more than 3 shots per attacker equals how many good guy rounds?
And I would really like to know the details of that police report b/c it's very likely that that homeowner died with an empty magazine in his hand.
Lesson learned: The life that a 10 round mag saves? It might not be your own....

I don't know the full details. It could be that all four people were accustomed to living outside the law and none of them had 10 round magazines. Still, it made me think.
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Old January 18, 2013, 02:53 PM   #15
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What I have been replying to people that ask about standard mags (to me, 17 rounds in my G17 is standard, the mag is not extended)

Are you immune to crimes? Have you ever been shot at? Do you think everyone is a perfect marksman? How do you deal with a home invasion robbery with 3 or more people that are intent are harming you, your children or raping your wife? Are you going to run to the phone?

For anyone that has been in a fire fight alone, you know that its not easy to hit your target when on the move or they are on the move or both.
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Old January 18, 2013, 06:34 PM   #16
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Ayoob said it very well, back in December:

Americans have historically modeled their choices of home protection and personal defense handguns on what the cops carried. When the police carried .38 revolvers as a rule, the .38 caliber revolver was the single most popular choice among armed citizens. In the 1980s and into the 1990s, cops switched en masse to semiautomatic pistols. So did the gun-buying public. Today, the most popular handgun among police seems to be the 16-shot, .40 caliber Glock semiautomatic. Not surprisingly, the general public has gone to pistols bracketing that caliber in power (9mm, .40, .45) with similar enthusiasm. The American police establishment has also largely switched from the 12 gauge shotgun which was also the traditional American home defense weapon, to the AR15 patrol rifle with 30-round magazine…and, not surprisingly, the law-abiding citizenry has followed suit there, too.

The reasoning is strikingly clear. The cops are the experts on the current criminal trends. If they have determined that a “high capacity” semiautomatic pistol and a .223 semiautomatic rifle with 30-round magazines are the best firearms for them to use to protect people like me and my family, they are obviously the best things for us to use to protect ourselves and our families .
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Old January 18, 2013, 07:09 PM   #17
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The reason is simple. The 2nd amendment exists so that we possess the ability to fight for our freedoms if the need arises. And we are allowed weaponry with the ability to do so.
Defense against criminals is only a added value to the Right to Keep and Bear. We are supposed to have weapons that are similar to what the military uses. We are the last line against an oppressive Government.
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Old January 18, 2013, 07:34 PM   #18
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Or ya can just carry a couple extra guns....
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Old January 18, 2013, 07:34 PM   #19
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I remember back in the 80's when I bought my first AR. It had a 30 rnd mag. I took it over to show my father and as he looked it over he asked me what I needed a gun like that for. My response was that the govt. has them, the police have them and the bad guys have them. I want one too!
My father was not a gun person but admited he could see the logic in that and that he couldn't argue against it.
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Old January 18, 2013, 07:38 PM   #20
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If I remember correctly, our issue M16's had 20 round magazines. (This was back in the early '70's). When we did our field training, we taped a few pairs together so all you had to do was pop it out, turn it over & re-insert.
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Old January 18, 2013, 09:03 PM   #21
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Twenty round magazines? The Generals thought you would waste ammunition.
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Old January 18, 2013, 09:14 PM   #22
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To the extent possible, I try not to engage in the Argument of Needs. My theory is that by engaging that argument, to some degree, you concede that your RKBA is connected to what you need.
A gunfight is not the time to learn new skills.

If you ever have a real need for more than a couple of magazines, your problem is not a shortage of magazines. It's a shortage of people on your side of the argument. -- Art Eatman
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Old January 18, 2013, 09:30 PM   #23
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Just to be clear, I actually think that recreation is a perfectly good and sufficient reason for continuing the legal private ownership of guns and accessories. Of course, there are certainly other important beneficial factors to gun ownership, and, even more to the point, we don't have to explain why we need guns to justify owning them because our right to own them is not based on having to provide a need.

That said, when a person says that they believe that gun ownership should be allowed so that people can defend themselves and then state that no one needs more than ten (or 7) rounds to accomplish the goal, the argument I have presented is useful.

Basically it makes it clear to a person who believes in the right to own guns for self-defense that restricting the round count of the firearm can significantly impair a citizen's ability to mount an effective defense.

It never hurts to demonstrate to a person that one of their preconceived notions is badly in error. If that person is at all disposed to rational thought, such a demonstration will force them to acknowledge that there is a possibility that their other preconceptions may also be wrong.

Not only is it tiresome to keep hearing the talking heads repeatedly chant the mantra that no law-abiding person needs more than 10 rounds without anyone ever showing why it's absolutely not true, it also encourages fence-sitters to join the antis because it appears that they have a point when no one can answer the question directly and decisively. While we know why it's a red herring, not everyone cares about the philosophy of the founding fathers as it applies to private gun ownership.

In short, while it is true that they are wrong to imply that "need" is the criteria that should be applied to go beyond what they consider to be a reasonable round count, it is also true that they are badly mistaken as to what a reasonable round count really is.

There's absolutely nothing wrong with pointing out both errors--in fact, it strengthens the argument considerably because effectively attacking what they believe to be "reasonable" with hard facts often resonates much more strongly than a discussion of the real meaning of the constitution and the philosophy of the founding fathers which they fundamentally disagree with anyway.

Some people aren't ever going to give any weight to the idea of inalienable rights--but it's pretty hard for them to ignore the fact that taking 5 rounds out of a law-abiding homeowner's gun could reduce his chances of surviving a home invasion by two persons from 70% to 35%.
Did you know that there is a TEXAS State Rifle Association?
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Old January 18, 2013, 11:28 PM   #24
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Then you can explain to'm why people other than White, Male, property owners ought to be able to vote.
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Old January 19, 2013, 02:08 AM   #25
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IMO, the whole term "high-capacity magazine" is rather arbitrary. Who ever decided that anything over ten rounds constitutes "high-capacity?" To me, 30 rounds for an AR-15 would constitute "standard capacity." Ten rounds would be "low-capacity."
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