The 9mm vs 45 ACP Debate: A Visual Aid...

My rule of thumb for carrying for self-defense, more or less in order:

1. Any gun is better than no gun and a reliable gun is better than an unreliable gun.
2. A hole in the right place is better than a hole in the wrong place.
3. A bullet that penetrates adequately is better than one that doesn't.
4. A big hole is better than a small one.
5. More holes are better than fewer holes.
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I would exchange 4 and 5.

The ability to control recoil and get back on target with follow up shots would seem to be the most critical factor in overall effectiveness in a defensive encounter.
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That's what makes it possible to get that "hole in the right place", which results more from chance, speed and combat accuracy than from aiming for where that hole should be.

I would place the ability to avoid or evade first, and the ability to draw and shoot timely second.

And then those other things.
 
I would exchange 4 and 5.
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That's the debate. I put bigger hole first because non-gun type people are more likely to understand one shot was fired in self-defense than multiple shots.
 
That's the debate. I put bigger hole first because non-gun type people are more likely to understand one shot was fired in self-defense than multiple shots.
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All competent trainers train people to shoot multiple shots rapidly under most circumstances, and anyone who can demonstrate a basis for having known that before a critical incident will be able to introduce expert testimony in support of that.

I cannot conceive of how a single shot fired at a fast moving assailant would have any reasonable likelihood of hitting anything critical.
 
rc said:
8 Rounds of 45 or 10 rounds of 40 will become the new normal in states were magazine capacity is limited. 9mm as a primary defensive arm only makes sense in compact guns and where mag capacity or lower recoil is an advantage. rc
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The Glock 30 and 30c will become more dominant, and 4" 1911's will become more popular than ever.
 
CDW4ME said:
Another 9mm / 45 visual aid, from handgunsmag.com:

federal_hst_ammo_11.jpg




Yea, I've read that they all "perform about the same", right.....

A hole approximately the size of a dime versus one the size of a quarter in the same spot, couldn't possibly make any difference .... :rolleyes:
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The funny thing about photographs...


...the closer an object is, to the camera, the bigger it looks.

In that picture, the 9mm is farthest back, while the .40 is the farthest forward.

See how big this guy's fish looks?

f3feac13e5eec08303707c8b34e8985a.jpg
 
8 Rounds of 45 or 10 rounds of 40 will become the new normal in states were magazine capacity is limited. 9mm as a primary defensive arm only makes sense in compact guns and where mag capacity or lower recoil is an advantage.
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Lower recoil is always an advantage for defensive shooting that does not involve animals

My 9MM holds eight rounds. There are no legal limits on capacity here.

It is not what I would call compact--it is single column, but it has a four inch barrel.

Some people who normally carry 9 MM pistols do carry .45s when they are in states where magazine capacity is limited. My current 9 MM and my .45 have the same capacity.
 
In the photograph of the expanded hollowpoints, the 9mm is only about a 1/4" behind the .40, not nearly enough to make it appear any smaller.
 
The differences in energy and weight are meaningless, except to the extent that they result in a difference in penetration.
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So we have this straight, according to you this is only true above 9mm.

The difference in expanded diameter is not meaningless, but it is not very great, either.
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So we have this straight, according to you this is only true above 9mm.
round and round OM goes
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The differences in energy and weight are meaningless, except to the extent that they result in a difference in penetration.
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So we have this straight, according to you this is only true above 9mm.
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Well, no, it's true for .25 ACP and .32 S&W and all the way through the standard service handguns.

When we consider rifle rounds, other things come into play.

To round out the discussion, velocity, mass, bullet shape, bullet construction, and sectional density together contribute to expansion and penetration.

The difference in expanded diameter is not meaningless, but it is not very great, either.
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So we have this straight, according to you this is only true above 9mm.
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Well, no. The experts tell us today that it is true in practice among the service calibers. Other than that, they mean nothing to us.

One does not find many experts the days who recommend the smaller calibers for primary carry.

The question was about the importance of three things: kinetic energy, weight, and expanded diameter. The first two do not directly stop assailants. The third can make a difference, but the amount of difference in effectiveness for relatively small differences in diameter has been questioned by experts.

I would not call the expanded diameter of a .32, such as it is, as close to that of a good .45 ACP. But between 9MM and .45 inclusive, when we are talking about the relative difference in the size of expanded bullets in the context of the size of a human chest and not a prairie dog, we are told by those who have studied the subject that the comparative difference is generally not very material.

I am not enough of a forensic anatomist to offer my own assessment.

I do accept that where the bullet enters the target and at what angle will make much more difference.

One of the top trainers recommends that everyone keep a copy of Gray's Anatomy on the shelf close to the chair.

I do not.
 
I would not call the expanded diameter of a .32, such as it is, as close to that of a good .45 ACP. But between 9MM and .45 inclusive, when we are talking about the relative difference in the size of expanded bullets in the context of the size of a human chest and not a prairie dog, we are told by those who have studied the subject that the comparative difference is generally not very material.
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In actually studying the subject myself and not just parroting what SOME expert says I find it absurd that expansion whan going from .45 to .6 (.45 being very doable by a 380 and what ball 45 is already) is somhow significant yet going from .6 to .85 is not.

Back to your circle OM
 
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In actually studying the subject myself and not just parroting what SOME expert says I find it absurd that expansion whan going from .45 to .6 (.45 beingvery doable by a 380 and what ball 45 is already) is somhow significant ...
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Has it been contended by "SOME expert" that going from .45 to .6 is "somehow significant"?

...yet going from .6 to .85 is not.
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I do not think that anyone has seriously contended that, either.

What most of the expertS are saying now is that the difference between the expanded diameter of a .40 (.72) and that of a 9 MM (.61) is considerably less important than the potential for shooting more rapidly.

Some of them also introduce the difference in capacity.

Back to your circle OM
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What?

Do yourself a favor and look into how many well regarded trainers have switched to the 9 MM.
 
Now, in case anyone needs reminding, the OP asked about the 124 grain 9, and about the difference between the 185 grain and 230 grain .45.

I replied replied that when I do carry a .45, I carry the higher bullet.

I also pointed out out that I had not put a lot of thought into it. My thought is that with a four inch barrel, it is probably a better choice.

But I choose to not try to overthink issues of pure terminal ballistics.

The thread drifted into the usual .45 vs 9 debate. The issues are really about the same as in the .40 vs 9 evolution.

We do see .45s in LEO and some military holsters, almost exclusively those of elite SWAT, Hostage rescue, and some MARSOC troops.

I think it is worth pointing out that the needs of those teams usually include precision shooting in going forward--not defending against an ambush by a charging attacker close range in a parking lot.
 
I do think its a fair point to evoke the fact that no one would chose 380 over 9mm for a defensive service sized pistol, yet we have many that would have you believe 40 and 45 has no advantage over 9mm.

In the end, I digress. I trust my life to 9mm almost daily. Im a cop, normally in plain clothes so concealment is important. I can choose between a 9mm Sig p290 or a 45acp p227. I choose the p290 for easy concealment most of the time. If there is a higher threat level (high risk warrant service, specific threat intelligence, etc.) I usually carry the 45acp. A debate can be had about more power vs more capacity... But 1) don't try to convince me that 45 has no power advantage over 9mm and 2) why the caliber war debate? Both calibers serve their purpose and there is no need to start a pee pee contest over it.
 
So now you agree that there is not a significant difference between 380 and 9mm?
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The practically significant difference between .380ACP and the service pistol calibers is in penetration. It is generally accepted that .380ACP with expanding ammunition can not be counted on to penetrate sufficiently to be considered a good choice for self-defense. It is generally accepted that all the service pistol calibers when used with expanding ammunition will penetrate sufficiently to be considered adequate for self-defense.

So yes, there is a significant difference--.380ACP does not reliably meet the penetration requirement for self-defense while the service pistol calibers do.
...I find it absurd that expansion whan going from .45 to .6 (.45 being very doable by a 380...
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The thing that makes the .380ACP significantly different from the service pistol calibers is not based on deficiencies in bullet diameter or expansion, it is specifically that the .380ACP, with typical self-defense ammo, can't reliably achieve the commonly accepted penetration threshold for self-defense.
 
The practically significant difference between .380ACP and the service pistol calibers is in penetration. It is generally accepted that .380ACP with expanding ammunition can not be counted on to penetrate sufficiently to be considered a good choice for self-defense. It is generally accepted that all the service pistol calibers when used with expanding ammunition will penetrate sufficiently to be considered adequate for self-defense.
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Ok so now we're worried about a little bit bigger expansion, I thought a little more expansion was insignificant and that recoil and penatration were the key.
 
The thing that makes the .380ACP significantly different from the service pistol calibers is not based on deficiencies in bullet diameter or expansion, it is specifically that the .380ACP, with typical self-defense ammo, can't reliably achieve the commonly accepted penetration threshold for self-defense.
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Does this hold true if we are discussing full "duty" size handguns and barrels or is it primarily a concern out of pocket pistols? Since we are making an argument that expanded bullet diameter differences are insignificant and penetration is key what about with FMJ rounds?
 
I have been spending an odd amount of time thinking about this thread. I don't think my objection is to the argument for 9MM or to the argument for .40, .45, 10MM or anything else. My objection is to the idea that the argument is demonstrably settled in favor of any particular pistol round. Its probably not limited to pistols - if I went into the rifle sub forum and declared that any game animal on earth could be taken with a .375 H+H and all other calibers were worth less we could have a really interesting discussion :).

What finally occurred to me: the arguments for 9MM are based on time of aimed fire - time differences that are measured in small fractions of a second. While I was shooting I noted I fired three shots and assessed the targets. I don't mean that I figured I was done it means I took a second to intentionally assess my shots and reaffirm my target (and in practice a clear shooting area, the area behind the target, and those things you are supposed to always be aware of). Is this the best thing to do? Probably not. Is there some value to it? Not certain as I have never been in a gun fight (nor do I intend to be) but I imagine the reason I was originally taught this had to do with combating tunnel vision though it may have gone to capacity limits of a revolver.

The fact of the matter is I am never going to be good enough to put 8 shots in that 6" circle in two seconds (or whatever the magic number is). The number of shots I am going to put in the circle in a reasonable amount of time (I have never used a shot timer) is three. Then pause. Then three more. Unless we are talking some big bore revolver with extreme recoil three is the magic number for me.
 
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