Ballistics From A Newbie's Perspective

S

Snort

New member
I had finally settled on a PPQ in 9mm for my first handgun, when out of the blue I decided to try an HK45C. Turns out I shoot it just as well. Consequently, I'm now trying to decide which caliber I want to go with. To that end, I want to make sure I'm understanding the ballistic properties of both. I'm hoping beyond hope that this will not turn into a "caliber war" thread, as I've read about a hundred of those over the past week.

Rather, I'm hoping for confirmation that what I believe I understand about these two calibers is actually how they function. If I'm wrong, I'd rather know now than before I pull the trigger on one or the other.

Expansion:
This one seems pretty straightforward. The .45 holds the edge regardless of what sort of round/load we're talking about. "Heavy" +P 9mm loads seem to do almost as well, but not quite. Talking about JHP, of course.

Trajectory:
From what I understand, 9mm shoots in a much more flat trajectory, meaning it's more accurate at extreme ranges, while .45 drops more quickly in comparison. Correct? This is, bizarrely, one of the traits I'm more concerned with, despite knowing it has little practical application; I am never going to be in a gunfight at 50+ yards with a pistol. Still, it bothers me about the .45 for some reason.

Energy:
This may be the statistic I understand the least; my understanding of it is kinetic energy applied by the impact of the round, which, I presume, would play some role in the amount of trauma done by the shot. .45 seems to retain its energy much better over distance than 9mm, which if my understanding of trajectory is correct, suggests that though the .45 is going to be less accurate at long ranges due to bullet drop, it's still going to hit harder if it hits. 9mm seems to bleed energy quickly.

Penetration:
This one's interesting. Penetration in ballistic gel is better with the .45, though again, "heavy" +P 9mm loads do almost identically. However, when we're talking about penetration of "protection" of some sort - heavy clothing, or of course ballistic vests - 9mm seems to be the clear winner. Yet, just to throw another wrench in the works, .45 seems to do better against actual barriers - car doors, walls, etc. Have I got all that right? If so, no idea how that could all be true.

Price:
.45's a lot more expensive. 9mm equals more practice, unless you're on an unlimited ammo budget, which I'm not.

Suppression:
A minor concern, but if I ever want to throw a can on the gun, it might become important. .45s are inherently subsonic, to my understanding, while you need to find certain subsonic loads for the 9mm. The .45's going to be louder regardless of being "easier" to suppress.

Am I missing any characteristics I should be considering? I don't know that understanding all of this for sure is going to help me any, but like I said, I want to make sure I do. Then I'll just have to decide how likely it is I'll ever be facing armored zombies advancing on me from the opposite endzone of a football field and decide accordingly.
 
Expansion - expansion for the sake of expansion is worse than useless.

Controlled expansion is the key/desired result.
The bullet should enter, travel an inch or two, then begin to expand. Maximum expansion should occur just as the bullet has entered the vitals.
In a perfect self defense world, the bullet would have achieved maximum expansion for the entire trip through the vitals and stop just as it hits the skin on the back.

No one single caliber holds an edge in this category.

However - higher velocities can generally be counted on to perform with more predictable results across a wider band of velocities - regardless of caliber.

Trajectory - it's a handgun, not a mortar. Don't worry about trajectory until it comes to the point that you have to. If you wanted to hunt w/a scoped pistol, then bullet drop out beyond 50 yards would matter. For now, just focus on other things.

Energy - the energy in foot pounds is a common unit across all calibers. Bullet weights and velocities and diameters may change, but, energy is energy. It's the most convenient way to compare one thing to another.
A .22mag, .38 spl., .45acp and 9mm can all be loaded to more or less the same energy levels - but - one will be a screamer and another a real flub.

Penetration - goes hand in hand with expansion. Sectional density is the key that unlocks the door to both.
If you understand the role of sectional density, expansion and penetration will fall into place.

Price - reload/handload ASAP. Loading manuals have more than just load data. They also go a long way towards demystifying the questions you asked.

I don't know that understanding all of this for sure is going to help me any, but like I said, I want to make sure I do
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I beg to differ w/you on that. The more you understand what's going on from the moment you pull the trigger until the bullet hits it's target, the better shot you will be.
 
You hit ALL the hot talking points!!

This borders on the old "Caliber War" threads, as you mention pretty much all of the hotly contested talking points. :eek:

For what it is worth I will throw my $0.02 in the kitty.


Expansion Hal and I tend to agree more than disagree on this one. Controlled expansion is more desirable than explosive expansion but, bullet performance and expansion (even controlled expansion) are not synonymous. There are a lot of non expanding bullet designs that will poke just as big of a hole as an expanding type bullet. The meplat, or frontal surface area of the bullet, coupled with the velocity of IMPACT is what determines the diameter of the wound channel. I won't get into my theories on how I believe this works, but I can tell you from experience that a non-expanding, 335 grain .45 caliber bullet with a large meplat (.360")will punch a 3/4" hole completely through the full length a deer when the impact velocity is around 1000FPS.

As expansion pertains to hollow point style bullets, most modern designs are engineered to expand at the operating velocities of the cartridge they intended for. Load them too far to either side of the intended velocities and you are likely to see no expansion on one extreme and explosive expansion and little penetration on the other extreme. Given my choice between different calibers, loaded with hollow points that have a track record of proper function at the given cartridges velocity range, I will choose the larger one pretty much every time. If it starts out larger, odds are that it will end up larger as well. Couple this with the heavier weights possible with larger bore diameters, and it really does add up to a potent recipe for performance. I will freely admit that I fit into the "Bigger is Gooder" camp when comparing only the performance aspect of handgun cartridges. Other factors can sway me to smaller calibers.

Trajectory Once again, I will agree with Hal. I can easily engage B-27 targets at 100 yards with either 9mm or .45ACP. The nine shoot flatter, but it really doesn't matter. I frequently use paper plates for targets at 100 yards. While every shot is not a hit, you would be amazed at how much easier they are to hit than what you may think. Trajectory with handguns, unless we are talking about hunting (and even then I may disagree), just doesn't matter.

Energy On this point, I will have to disagree with Hal a bit. Energy in a handgun, IMHO, just doesn't matter. Handguns do not kill quite like a rifle does, in terms of energy, because of the comparatively low velocities of handguns. Handguns suitable for defensive use are so close in terms of energy that it just doesn't matter.

Penetration This is a subject that I think is largely misunderstood. Most defensive ammo is tested in ballistic gel, and far too many people think that gel tests will tell you what a given load will do in a human body. THIS IS NOT TRUE! Gel tests are simply a calibrated standard for measuring bullet performance. What a bullet does in gel tells you...what a bullet does in gel. Granted, ballistic gelatin can give indications of what a bullet MAY do in tissue, but it fails to be completely accurate because of the variety of tissue types encountered in any living creature. Not to mention bone, clothing, barriers, shot placement, and a host of other variables.

Generally speaking, we want a bullet to penetrate deep enough to reach vital organs. But, what does that really mean? Reaching the vitals of a person facing you is vastly different than if the bullet must first penetrate through the shoulder from the side to reach the vitals. What bout if the person is facing you but pointing a gun in a isosceles type stance with both arms extended toward you? The odds are that you will be so focused on their gun that you rounds are quite likely to hit their arms. This is something that is frequently seen in both law enforcement and civilian shootings. The bullet must have sufficient penetration to perform in a wide variety of circumstances.

It seems that you can never have a discussion about defensive shooting without someone bringing up the subject of over-penetration. For what ever it is worth, here is my opinion. DON"T WORRY ABOUT IT! That's right, forget about it altogether. IMO, it is no factor at all. Think about this. If you are concerned about injuring or killing someone because your bullet passed through the bad guy and struck them, should you even be taking the shot? What happened to be aware of your target and what is beyond it? Take a look at the hit percentages in gunfights. They are not high percentages. I am far more concerned with where each bullet is going than I am with whether or not the one that hits the bad guy might go all the way through as cause collateral damage. Holes that go all the way through a threat are a good thing! They produce lots of bleeding as a general rule, and contrary to what many believe, handguns do not have "stopping" or "knockdown" power. They kill by reducing the blood pressure to zero and by destroying the tissue of vital organs, or severing the contact between the brain and the body.


Price 9MM is pretty much always going to be cheaper than .45. This is largely because every single component of a loaded cartridge is sold by weight. It requires more raw materials to make a round of .45 than it does to make a 9mm. My answer is to reload, and I even cast my own bullets for all of my handguns that I shoot regularly. You won't really save any money. You will just shoot more for the same investment.

Suppression Both are great cartridges for suppressors! The .45 starts out subsonic and the 9mm can be easily had in subsonic loadings. Both can easily be suppressed to the point that hearing protection is not needed for comfort, but still recommended for prevention of hearing loss.

As far as the .45 being louder, this is not necessarily the case. The 9mm operates at a maximum pressure of 35,000psi and the .45 at 19,900psi. The gases escaping behind the bullet and then rapidly expanding is what causes the report of a gun shot. Smaller bores with higher pressures are quite often louder and have a sharper crack to them than larger bores at lower pressure.

I don't know that understanding all of this for sure is going to help me any
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Understanding always helps! There are probably no answers that everyone will agree with, but, having a working knowledge of both internal and external ballistics can help you make decisions based on what you want to accomplish. It is also a subject of great fascination that provides for hours of lively debate around the campfire or in forums. Just wait, you will see. Someone will be along shortly to tell you how full of crap my post is. Read what they say, do your own research and you decide what information is worthwhile and what isn't.

JW
 
Thanks for the responses and deeper explanations, guys.

In layman's terms, though, are the understandings I laid out more or less correct? In other words, will a .45 experience more drop than a 9mm? Will a 9mm penetrate protection better?

As far as shooting at targets 100 yards away...trajectory tables I've found show that a standard .45 should be experiencing almost two feet of bullet drop at that distance. Are you taking that into account when target shooting at that range, or am I missing something?
 
You're over thinking it snort and worrying too much, but I understand I've been there myself.

You are better off with your 9mm PPQ than you would be with a pistol chambered in .45 ACP.

The small ballistic advantage the .45 ACP has, is outweighed by the 9mm's increased capacity and more controllable recoil. Plus, for the non-rich, non-handloader more ammo to practice with.

Just practice, practice, practice with your PPQ and don't worry about ballistics. Any of the quality defense 9mm ammo that shoots accurately and functions well in your pistol will be fine.
 
Energy On this point, I will have to disagree with Hal a bit. Energy in a handgun, IMHO, just doesn't matter. Handguns do not kill quite like a rifle does, in terms of energy, because of the comparatively low velocities of handguns. Handguns suitable for defensive use are so close in terms of energy that it just doesn't matter.
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Flyboy,
We're on exactly the same page.
IMHO - way too much emphasis is placed on energy as an end all/be all indicator of how a given round will perform.

I'm right with you that, in a handgun, it simply doesn't matter.

The only time I use the energy figures is like I stated above - to compare the terminal performace of round X vs round Y.

Snort,
Yes - a 230 grain .45 going 850 fps will drop more than a 124 grain 9mm going 1100 fps.
However - that's only a part of the story.
What's more important is how much velocity each round sheds since it's the loss of velocity that causes the bullet to drop.
Change that 230 gr .45acp to a .45 Colt (same bullet/different cartridge) and increase the velocity to 1100 fps. and the trajectory flattens out.

Re: 9mm vs .45 for penetration.
In simple non-ballistic terms I'll try to explain sectional density.
Look at a 115 grain FMJ 9mm bullet and a 230 grain FMJ .45acp.
The 9mm has a "pointy" nose. Think of that as a ice pick.
The .45acp has a more "rounded" nose. Think of that as the end of an half sharpened pencil.

Drive each into a watermelon using the same amount of force & the ice pick will go in deeper.
(Please note that this is nowhere near the correct explanation/information on sectional density - however- it gives you the right idea that smaller frontal area will penetratre deeper with less effort)

Now - let's change things a bit and get inline with what sectional density actually is.

Take a 230 grain .45 acp. and a 147 grain 9mm.
The sectional density of each bullet is nearly the same @ .161 and .167.
Drive them at similar velocities and guess what?
They will penetrate gel to similar depths w/the edge going to the .45acp due to it's increased mass.

That same formula/idea holds true for all calibers.
What's though of as "standard weight" for a bullet of a given caliber will nearly always figure out to have a sectional density of ~ .11 to ~.19
40 grain .22 = .11
95 grain .380acp = .108 ***
158 grain .38/.357 mag = .177
246/240 grain .44spl/.44mag = .192
255 grain .45 Colt = .177

If you pour over chart after chart/test after test dealing with penetration, you'll see a pattern develop.
"Standard weights" of bullets at "standard velocites" with similar sectional density will all penetrate gel to nearly the same depth.

(end part one)
 
In my informal testing over the years,Ive found 9x19 to be a better penetrator than .45acp using FMJ,particularly against barriers.Against a cars windshield,Ive seen .45acp FMJ simply deflect off of the windshield while 9x19 FMJ cuts through like a hot knife through butter.Like others have said,I wouldnt be too concerned with trajectory.
:)
 
Trajectory:
From what I understand, 9mm shoots in a much more flat trajectory, meaning it's more accurate at extreme ranges, while .45 drops more quickly in comparison. Correct? This is, bizarrely, one of the traits I'm more concerned with, despite knowing it has little practical application; I am never going to be in a gunfight at 50+ yards with a pistol. Still, it bothers me about the .45 for some reason.
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It's not a big deal. I opened a couple of tabs to look at numbers from factory ammunition. At 50 yards, common Remington 9mm ammo has a midrange trajectory of about 0.8 inches, while common Remington .45 ammo has a midrange trajectory of about 1.6 inches. Just for giggles, I went into my closet and measured the difference between buttons on my dress shirts. 3.5 inches. So, to put it into perspective, you're looking at less than the difference between two buttons on a mans dress shirt. I'd bet, at 50 yards, your aiming error would be bigger than that.

However, your concern highlights one of the big misconceptions of folks who pore over such numbers. It's long been my contention, backed by long experience, that the hands-down best handgun for an officer working a rural area is the .357 magnum revolver. When the ranges start to stretch out it's nice to have a handgun that will put a heavy bullet on the target. If I had to go back to working a rural patrol area, I'd be damned tempted to take along my old Model 28.
 
(part two)

Now let's alter the bullet by adding expansion.
All expansion does is change the frontal area of the bullet.
As the frontal area increases (assuming the jacket and bullet stay intact), he sectional density goes down.
As the sectional density goes down, the bullets ability to penetrate follows it down.
Change the 230 grain .45acp to a hollow point and add controlld expansion to the mix.

@ 10% expansion (roughly .50 caliber) - as the nose begins to mushroom - the sectional density goes down to .133

@ 25% expansion (roughly .56 caliber) the sectional density goes down to .105

@ 40% expansion (roughy .63 caliber) the sectional density has dropped to .083

@ 60% expansion (roughly .72 caliber) the sectional density has dropped to .063

Ok - now back to the original question - will a 9mm penetrate protection better.(than a .45acp)?
Not really to it depends on far too many things to say one way or the other.
A 230 grain .45 using a FMJ will penetrate more 2x4's than a 124 grain 9mm hollow point.
A 147 grain 9mm FMJ and a 230 grain .45acp FMJ will penetrate nearlly the same number of 2x4's.
A 147 grain 9mm FMJ will go through more 2x4's than a 185 grain .45acp hollow point.

Now the three *** from the first part by the .380 acp.
If you've caught the general drift of what I've been trying to get across, you should be able to tell me @ this point why the .380acp is sometimes knocked for it's inability to penetrate.
 
nate45 said:
You're over thinking it snort and worrying too much, but I understand I've been there myself.

You are better off with your 9mm PPQ than you would be with a pistol chambered in .45 ACP.

The small ballistic advantage the .45 ACP has, is outweighed by the 9mm's increased capacity and more controllable recoil. Plus, for the non-rich, non-handloader more ammo to practice with.

Just practice, practice, practice with your PPQ and don't worry about ballistics. Any of the quality defense 9mm ammo that shoots accurately and functions well in your pistol will be fine.
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Truth be told, I'm leaning heavily towards the HK45C. Can't really explain why. I would say I'm marginally better with the PPQ - and by marginally, I do mean very marginally - but I also attribute that to most definitely flinching with the .45, which I'm led to believe will go away with practice.

Basically, this thread was started to try and find some edge to drive me back towards 9mm, aside from capacity and cost. I realize those are both important, but something like, say, better long-range accuracy or better protection penetration? That might do the trick.

And I realize that answer's likely to spark a caliber war, so apologies in advance.
 
I realize those are both important, but something like, say, better long-range accuracy or better protection penetration?
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I would disagree that capacity is important. Consider this; The likelihood of ever having to actually use your carry gun is very remote. A very tiny percentage of people who carry ever have to actually discharge their firearm in defense of life. An even smaller percentage shoot more than two or three rounds. It is probably likely that those who fire more than a few rounds, do so, as much or more, because of being poorly trained or out of practice, rather than because the situation presents multiple threats.

In fourteen years of law enforcement work, including nine years on SWAT, I was engaged in multiple shootings. Never once did I shoot a magazine dry. It was very seldom that I discharged more than four or five rounds. It just really does not happen often. This is not to say that capacity cannot make a a difference, but, I think that relying on capacity rather than competence and mindset, is a sure-fire way to be on the receiving end of criminal charges, civil liability, or worse yet, your own funeral. Opinions will vary, so take it for what it is worth.

JW
 
Trajectory?

Handgun defense is a short range proposition and trajectory should not enter the equation unless you're thinking along survivalist, last man standing, lines. Even the FBI protocol doesn't worry about trajectory.

Today's advanced handgun projectiles offer both penetration with expansion. When all is said and done and after you've read all
568,582,239,721,260,000,000,000,000,000, threads on the topic, there's very little difference in terminal effect when comparable bullets are used in any modern caliber above .380 ACP. So, don't agonize over every last foot-pound of energy or sliver of expansion. My home defense guns are .45 ACP but my carry guns are 9mm and I don't feel the least bit undergunned.
 
As far as trajectory goes, it doesn't matter what you're shooting. If you're shooting parallel to the ground everything will hit the ground at the same time.

Doesn't matter if it's a 115gr 9mm or a 230gr .45.

The difference is the 9mm is going faster, so it covers more ground before hitting the earth (assuming it doesn't hit anything along the way).

In fact, if you dropped a penny from your hand at the same time you fired the gun both would hit the ground at the same time.
 
.45 ACP deflects off a car's windshield?...That statement strains credibility...and I'll readily grant that a 9mm FMJ will penetrate farther in any medium you care to test, than a .45 ACP...Rod
 
:confused:
I dont know what to tell you.???
I was there and pulled the triggers.The 9x19 came out of a compensated Hi-Point and the .45acp came out of a 5" 1911.
 
I was there and pulled the triggers.The 9x19 came out of a compensated Hi-Point and the .45acp came out of a 5" 1911.
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Doesn't surprise or shock me in any way...
One knock against the old police 158 grain .38spl RNL was that it would deflect off windshields.
Both the 9mm Luger and the .357magnum would go through the windshield.
Both the .45acp and the .38spl RNL have similar nose profiles and velocities.
 
I just typed like a 4 paragraph reply and it got deleted, so I'm just going to summarize ...

I settled on the .40SW. It has more power then the 9mm, more penetration, and about the same capacity. I'm sure a lot of people will dog on the .40, but I don't care and neither should you. The 9mm has been used successfully for a very long time, so I'm sure that a .40 with a bigger bullet and more power will do just fine. I've wanted a 1911 for a long time, but I just can't bring myself to get one because I know that I'll practice a lot less the I would with my 9mm. I've always heard that it's not what you shoot but how you shoot it. Another reason why I got the .40 over the .45 is penetration. I'm sure that at reasonable distances shooting right at a bad guy a .45 would do great, but what about doors, windshields, barriers? I would not put my faith in a .45, already subsonic before even leaving the barrel, to go through barriers.

Some things to consider with a .40 though are ammo and recoil. When I first got the .40 it was $2 more per box then 9mm. It's gone up and down since then it seems like. I've seen it as low as $12 and as high as $16 for a box of 50. Not great but still better the .45ACP. The recoil is definitely worth mentioning though. It's AT LEAST 2x more then a 9mm. It did take some getting used to, but I'm as good with my .40 now as I am with my 9mm. The first 5 times I shot it the skinned my thumb and now 9mms feel like BB guns, literally. I don't want to make it sound horrible, but it is pretty shocking if all your used to is a 9mm. It also has more recoil then a 357 Magnum come to think of it. It probably has a lot to do with it being a polymer gun and the 357 being under loaded and steel frame but it is what it is. I almost like the recoil because I know if it hurts my hand that bad God help the bad guy.

Here's some ballistics for your reading pleasures. This should also help with the .40 haters:

1. 9mm 124gr +P - Velocity: 1220, Energy: 410

2. 45ACP 230gr - Velocity: 890, Energy: 404

3. 40SW 155gr - Velocity: 1200, Energy: 496

4. 40SW 180gr - Velocity: 1025, Energy: 420

^ That speaks for itself. I'm not making that up, it's coming straight from the Speer ballistics tables located here: http://www.speer-ammo.com/ballistics/ammo.aspx

In my .40 I carry 1 magazine(15 rounds) with 180gr FMJ ammo in case I need to go through barriers, and another magazine with the 155gr putting out close to 500lbs of energy. I'll take that over a 357 Magnum any day. Even the heaviest .40 bullet is better then the 9mm +P bullet. That says something to me. Anyways good luck man.
 
Trajectory should not be an issue for SD range shootings.

While you might be shooting at a target far enough away, your already bad day (you are in a gunfight) has reached standing so bad as to truly be dismal.

Trajectory does not affect accuracy, as long as it is repeatable.

It will be a long time before you can approach the accuracy of almost any decent quality handing in 9mm or .45 ACP.

On human size targets out to at least 50 yards (and actually even further) put the site on the target and fire.

Either 9mm or .45 ACP is going to hit the target just fine if you do your part.

You are far more likely to miss to the side than elevation.
 
I think you are focusing on some factors that are either marginal or nothing to worry about.

I would focus on a few factors, them being: Controlability, penetration, and capacity. (cost also if you will).

Expansion between major calibers is usually too little to worry about. Energy, velocity, and SD are factors that play into penetration. If you have penetration, the others are fine. Trajectory is a non-factor.
 
If you shoot someone from far enough away for trajectory to matter, you are going to have a heck of a time convincing a judge and jury that it was self defense and not murder.
 
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