9mm & .45ACP : why doesn't size matter?

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FUD

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I haven't posted one of these in a while and so it's time for the stupid question of the day ...

I was cleaning some of my guns and I looked down the barrel of a .45ACP (S&W4513) and that of a 9mm (S&W3913) and even though the difference in size is only 0.1", that's still a much bigger hole when you compare the two of them next to each other.

It would appear to me that the .45ACP would do a whole lot more damage than a 9mm. Yet, both Marshall & Sanow and even The Fackerites rate some 9mm rounds as being as effective (or even more effective) than .45ACP rounds. I've even posted and quoted some of this data myself ...
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... My question is: Looking at the size of these two (the 9mm & the .45ACP), how can this be possible?
Share what you know, learn what you don't -- FUD
fud-nra.gif
 
Good morning, Fud. This is strictly a layman's opinion, but I suggest you make one other "common sense" evaluation. Compare the .45 ACP and 9mm bullets -- you're right, there's about a 0.1 inch diameter delta -- to the mass, size, and girth of your center-body mass. I'm not being derisive or cynical; the point is they are both mighty small when measured against the dimensions of an adult.

Therefore, I suggest (and I certainly am not a medical professional) that the damage done by either round is much more a function of what it hits/destroys -- which is why accurate shot placement is THE crucial variable -- than the marginal differences in the effects generated by either round.

I will now charge the fire hoses and don my Nomex suit, since I've no doubt offended both the "large and slow" and the "small and fast" crowds.

Warm regards.


[This message has been edited by RWK (edited August 03, 2000).]
 
Common sense suggests that all things being equal (equal barrel lenght, equal shaped bullets, equal accuracy), the .45 should do more damage than a 9mm. Sure, a +p+ 9mm that expands perfectly will do more damage than an underloaded .45 which fails to expand.
 
You must factor in speed when dealing with hollow point expansion. This is a most important component.
 
If bullet material is the same (lead) the expansion percentage is the same in proportion to the mass and velocity of the bullet.
A larger bullet will require larger velocity to reach the same expansion percentage therefore, the 45ACP would need a higher velocity to reach the same expansion percentage as the 9mm. However, a 70% expansion in the 45ACP is larger then 70% expansion in the 9mm.

The factor that is not talked about is energy dispacement. The 45ACP having greater mass will have greater energy dispacement.
If a 300pd man punches you with equal velocity as a 100pd man, which one do you think will hurt more?

I don't understand why we have to scientifically expalin something that just recquires commen sense.

------------------
"It is easier to get out of jail then it is a morgue"
Live long and defend yourself!
John 3:16
NRA lifer
GOA
GSSF
KABA

[This message has been edited by leedesert (edited August 03, 2000).]
 
The main advantage that I see with a heavier bullet is that it is less likely to deflect when hitting an obsticle. This could be a branch, door, rib, etc. When this happens, the heavier bullet is more likely to remain on course.

leedesert, your punching scenario doesn't hold up. Think about it.
 
In most comparisons, an expanding bullet is used in both calibers. Since expansion is a product of velocity, the faster 9mm bullet expands more and its frontal area becomes (about) the same size as that of the .45 bullet which does not expand as much.

In any living target, barring exotic stuff like cyanide bullets and fish poison projectiles, shot placement matters far more than any kind of "magic" bullet, and the ability to remain calm and place a shot is more important than a panicky spraying of lead in the hope of hitting something.

Jim
 
Personally, regardless of caliber, I always thought penetration, the ability of a given load to get to where it needs to be, was most important.

What difference does it make how big and fat a cartridge is, how much it expands in whatever, or how much energy it dumps on target, if it doesn't get to anything important?

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For God so loved the world that he gave his onlly begoten Son...
 
FUD, how well do you shoot each caliber?

How is your performance based on accuracy and split time for a COM shot and followup with different guns using a top quality round in each?

That's more important than the MS/GOAT/JELLY
/FPS stuff. Graph that data.
 
Okay to start with nothing is really being held constant.

I am not sure what load the 9mm 124 +P+ load is but will assume it is near nato pressures in which case you can drive a 124 grain bullet in the 1350 to 1400 fps range with a 5" barrel [note almost the same as the 357/125 JHP]. Now most 9's have a 4" or less barrel. While the 45's use 5" barrels for their nominal specs.

The 45/185 +P will do around 1150 or a bit more from a 5" barrel. And the standard pressure 230 will do 830 to 860 or so depending on load.

That the bigger bore does more damage thing would only be true if the penetrate to the same depth at the same velocity. Think of the bullets as boats in the water. They throw a bow wave ahead of them and it can knock things over. The faster you go the bigger the bow wave [though it isn't a one to one ratio]. That is part of the reason rifles do so much more damage than handguns is because there is a level IIRC around 2200 fps impact velocity, where the "bow wave" gets big/strong enough to break small bones and smash soft tissue hard enough it breaks. So a 223 or 308 bullet, both smaller than a 32 acp, do more damage than a 45 acp because or their velocity and the "bow wave" it creates.

So that is part of the problem. The other thing is honestly the body won't know the difference between a .355" bullet and a .451" bullet. A medical examiner can NOT tell caliber of gun used to shoot someone from the wound. There just isn't enough difference. If they recover the bullet that is different story.

The reality is bullet placement and bullet CONSTRUCTION matter more than caliber. And rifle velocity would help even more. If one is talking facts.

On the other hand a fight is a mainly a question of mindset IMHO. And I agree with you that the 45 [or 44] sure SEEMS more large & powerful when you hold it in your hand or compare it to a 9mm or 357.

So pick what you feel is most impressive. Or what you have the most confidence in. And then try to have complete faith in your choice while having a Plan B for what to do after the 110 lb goblin takes all 30 rounds from your favorite pistol and still keeps coming [wooden stake thru the heart?].
 
FUD--a point of curiosity. The 9mm in your table is +P+. However, AFAIK, most 9mm in use by police and civilians is not +P+. I believe that even NATO 9mm is about the equivalent of only +P. So, what would the performance figures be for standard pressure and +P 9mm?

TIA.
 
Here is a stupid question, but one that I have been thinking about:

How much of a "one-shot-stop" is subjective to the shootee (is that a word)?

ie: Which shot would cause the most mental trauma? (things to consider: the "slam" or shock of the hit, pain, etc)

for instance, a long knife may do more actual physical damage to a person, but hurts and stuns less than a blow from a baseball bat (I am thinking center of mass hit, not to the head). The person stabbed often still fights, while the person "batted" would probably not get back up so fast. However, the person batted will probably survive, whereas the stabbed person may not.

Any comments?
 
Leeds-

Energy (kinetic) = 1/2 m * V^2.

An increase in mass will only linearly effect the energy, while an increase in velocity raises the energy by a square.

The 300# hammer will impart 3 times as much energy as the 100# hammer.

A 100# hammer traveling 3 times faster than another 100# hammer will impart (3x3) 9 times as much energy.

Smaller and faster can actually impart more energy than large and slow. I stripped off the constants that would cancel out.

(300# * 1 ft/sec) = (not) 100 * 3^2
300 or 900 = 600 ft-lbs diff.

Forgive the butchering of units.

However, the acceleration paths of the bullets are limited in length so the slow and big can accelerate to its potential, but limits the smaller bullets to a tangible velocity. As long as barrels are say 4", the two bullets will impart the same (roughly) energy.

I assume that it is the swirling gasses in the barrel that impart twist on the bullet. The bullet "hydroplanes" in the barrel on the gasses. Since a 9 mm bullet is only 0.1" smaller, but usually weighs (230 gr - 115 gr) 115 gr less than a 45. It will take considerably more gas to twist the 45 vs 9mm. Area limits gas flow at sonic velocities, therefore an increase of area greater than the difference .1 is necessary to get enough gas to twist the bullet.

I hope this helps.
 
The most convincing thing I've read is that FBI article explaining that there actually (other than CNS hits) is no real reason for someone hit with a handgun to stop other than blood loss or psychological factor of "I've been hit, people hit on TV drop, I must drop".

However, everything I see comparing 9mm performance to 45 has the bullet expanding.

I have a story from a local cop who witnessed this - perp shot through silk & through the heart. Some 9mm hollowpoint thru a full sized gun. Perp walked away, sat down and died. Bullet was undeformed enough to be reloaded again!!

Now this is not saying that a 45 would have done better in this situation - evidence shows that you can last a long time without the heart even assuming it is destroyed. But there IS a worst case where the 9mm does not expand. And what happens to a good expander when it hits bone near surface (i.e. rib) and THEN goes through? What about partially hitting bone?

Also, I'm not one advocating that the extra 45 energy in and of itself makes a big difference in the wound. However, how much energy is spent breaking a bone? What is left for bullet performance?

In the best case 9mm may equal the 45. But what about the worst case? My guess is this worst case would be hardball vs. hardball, thru bone.


Battler.
 
Jimmy, you are correct that the +P+ is a LEO round only. I used it as an example in comparing the best available loads. My question wasn't aimed at what we should use for self defense -- a 9mm or a .45ACP but WHY would a smaller bullet be more effective than the larger one and a number of post'ers have provided some pretty good replies.
 
Remember FUD,

The energy of the bullet must be absorbed by the body. The bullet slows due to the resistance of flesh. As long as the energy of the bullet excedes the flesh absorbtion, the flesh will disintigrate in front of and near the bullet. Too much energy, 44 mag too close, will pass through the body and leave a tiny hole. As the bullet energy level lowers, more and more flesh will be called on to detract energy (bigger wounds).

The speed and cross sectional area at impact is going to make the most difference in wounds.

I own a 40 and do not care why people think their size is better than the other. Ask any 45 person if they want to take a hit from that pu$$y 9mm round. Or ask any 9mm person if they would like to outrun that big, slow bullet aimed at the back of their heads.
 
Nato level is above +P+ for US loads. WE really underload the 9mm and 357. Get a VihtaVuori Oy Reloading manual or other one that lists loads to European specs [Note the manual I mention has both US and European specs you have to look at the loads for Europe to see the higher pressure loads].

hube1236: First Kinetic Energy and Momentum equations are used in physics and are only valid there when both target and projectile do NOT change shape or deform. When you shoot things usually both the target and bullet deform. It takes energy to mushroom the bullet...that is part of the reason why solids penetrate deeper [other part is smaller cross section]. It is rifling that imparts twist on bullets not the gasses. Other wise smooth bores [ie shot guns] would have spin stablized slugs without having to use rifled barrels.
 
A police woman took a 357 magnum in the heart in a classic case and still took down her opponent. Most of the pseudoscience of all sides says the 357 is tops. So, blood loss takes a finite time and you can still keep going for that.

Everyone ignores my shooter comment. I assure you that practicing your skills are infinitely more important than this stuff.

If you don't shoot well - who cares. What quality round do you shoot well? Not what round shoots up jello, a goat or some anecdote of questionable reliability.

Many very skilled trainers shoot 9mms. They would hit you first, while you were still farting around with your 15 mm JHSPXT Gold Hollow Talon Buzzsaw round.

But it is more fun to talk the techy than the practice. :)
 
I have been sitting idley by and reading this post off and on. I will ahve to say that EnochGale is so correct. Who really cares about the technical bull of bullet construction and terminal performance. The real emphasis should be placed on shooter skill and shot placement. A .22 short will kill someone if the shot placement is correct. A.45 ACP will not kill anyone 13 rounds later if you are hitting the trees and the houses behind your aggressor. I prefer 9mm and 40 S&W over the .45 ACP simply because I can shoot them good. I don't care what weapon my attacker has...I am confident in my weapon and my abilities as long as I have my Beretta 92 loaded with 16 rounds of +P 124 gr Gold Dots coming out of that 5" barrel at 1300 fps (handloads). Will it take all 16 rounds? Hope not. But my shots will hit the vital organs. Way to go EnochGale!
 
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