Question regarding handgun caliber ballistics

[Lapietra]

Hello to all,

I spend a fair amount of time on the various firearms forums trying to stay current on advances in handgun caliber ballistics and performance. I have always gone with shoot the heaviest caliber you can handle type of thinking when it comes to SD.

But what I struggle to translate is the true impact of the bullets as prescribed by the various ballistics tables.

For example if a 9mm 124gr +p has velocity of 1200fps and a muzzle energy of 420 ft/lbs; is the bullet going to hit just as hard or perform just as well as a .40 cal 180gr traveling at 1000 fps with 410 ft/lbs of muzzle energy?

Is seems to me that the ammo manufacturers are pushing lighter bullets faster to get to the level of muzzle energy. But I dont know if I am correct.

Does muzzle energy actually translate to how hard a bullet will hit?

I sure would hate to choose a caliber in a low bullet weight at high velocity only to find out it sheds its energy upon impact or something like that becuase it was not heavy enough.

Thanks in advance for any input you may have.

Lap

[Sam]

Read this post from DocGKR, an expert on the field:

http://www.m4carbine.net/forumdisplay.php?f=91

[Lapietra]

Thanks Sam, that certainly was a good read. I agree in choosing the platform to shoot from and not letting the caliber dictate. But within a given caliber I want to make intelligent choices about the caliber I am good with, which is why I am focusing on ballistics.

For example when I shoot 180gr and 165 gr .40 cal FMJ's at my steel targets you can see and hear the difference than when I shoot 115gr or 124gr 9mm. I like the way the 40 hits but certainly am more accurate with the 9mm with regards to control and followup shots, especially one handed.

Thus if the ballistics tables translate as per my question regarding muzzle energy I would look to get 9mm that hits as hard as the .40. If not I would rather spend my time practicing with the .40 for SD just because of my own perceptions.

[Sam]

I think the point of that article was that as long as you are shooting a duty caliber (9, 40 or 45) you are good to go. There is a difference in ballistics between the three but they are all acceptable for self defense use. It really boils down to what caliber you shoot well and what platform you shoot well. I shoot 9mm because it is cheap, 9mm magazines typically hold more rounds than other caliber magazines in non restricted forms and I can control it easier than other rounds. I don't really worry about what gains I may receive if I moved up to a 40 or 45 because the body is elastic and irregular and those gains are not necessarily translated into better penetration or better cavities on humans.

[hyperion.excal]

recently where was a big troll thread about the 9mm vs 45 and i remember someone mentioned that in his department he had officers who uses 147gr 9mm and bad guys wont go down and the department switched to 40SW and never had any problems with guys going down since then. If you look around im sure you can find it.

Personally in 40SW i love the 180gr i can shoot it all day long with no follow up shots problems 165gr however is a different story, they are a little more powerful and my follow up shots arent as accurate. I know if i practice with 165gr i can shoot it as accurately as 180gr but i settled with 180 as my #1 choice.

[Lapietra]

Hyperion.excal ,

My current choice for SD/HD is .40 180gr as well. What started me on this kick was I read an article about the NYPD using speer gold dot 124+P. When I looked up the ballistics the 124+p round it showed 420 ft/lbs of muzzle energy. I then looked up 180gr HST wich says 410 ft/lbs of muzzle energy. So does that mean the 124+p hits as hard as the 180gr HST? Or am I not reading that right?

[hyperion.excal]

Hyperion.excal ,

My current choice for SD/HD is .40 180gr as well. What started me on this kick was I read an article about the NYPD using speer gold dot 124+P. When I looked up the ballistics the 124+p round it showed 420 ft/lbs of muzzle energy. I then looked up 180gr HST wich says 410 ft/lbs of muzzle energy. So does that mean the 124+p hits as hard as the 180gr HST? Or am I not reading that right?

Im not a 9mm expert but i know that a standard SAAMI or factory specifications for 9mm will not come close to the power of 40SW.

To be in the same level as the 40SW the 9mm will need (+p) or (+p+) more powder and or a heavier projectile. But this rises the debate of being (too much) too much PSi your gun can handle. Too much pressure can be bad for your firearm thats why there are firearm manufacturers that point out not to use these loads, and they will not fix your gun if the damage is caused be these loads.

But even with +P loads i will not count out the 40SW. I believe in the old saying "shot placement > caliber". I completely agree with this statement. I know where to place my shots and knowing that 40 will make bigger holes on the bad guys just makes it a whole lot better

There is a reason why the FBI chose the 40 and i believe in the same reason. Load the 40 proudly.

[slikna99]

Both energy and momentum play a part in this, as well as surface area. Normally speaking I would pick the heavy for caliber load, but there are exceptions. 180gr in .40 tends to be an under-powered load compared to the 165gr loadings. Why, because 180gr is the same bullet used in the 10mm casing, and now that we trimmed down the case to make .40 but retained the same bullet, it can no longer be pushed to the same velocity. Remember when you used to hear of the kato in glocks? A lot of factory loads using 180gr have been powered down to account for variations and make sure there are no accidents. The 165gr hst has more energy and momentum than the 180gr counterpart.

Given a certain caliber, if the bullets have the same energy, whichever one carries the most momentum is going to transfer that energy over the most distance. It gets confusing when moving to other calibers because they have less or more drag, but I would still say which ever has the most energy AND momentum is what I would chose.

[Sunday]

Hyperion.excal ,

My current choice for SD/HD is .40 180gr as well. What started me on this kick was I read an article about the NYPD using speer gold dot 124+P. When I looked up the ballistics the 124+p round it showed 420 ft/lbs of muzzle energy. I then looked up 180gr HST wich says 410 ft/lbs of muzzle energy. So does that mean the 124+p hits as hard as the 180gr HST? Or am I not reading that right?

IMO muzzle energy really means nothing.

[mixicus]

Muzzle energy is one factor in how "hard a round hits". The projectile still needs to hold together upon impact to deliver the energy in a useful manner. It must have a certain amount of penetration. Testing protocols such as the FBI's, highly value loads that deliver a projectile about 12" into the ballistic gelatin. You can take a look at the test criteria or read up on Dr. Gary Roberts work for more details.

If you look at quality testing data, compare 9mm, .40S&W and .45 ACP in the same brand/family (i.e. Winchester T series). This should mean the bullet construction is the same. All perform about the same against media like bare gelatin, denim-gelatin and heavy cloth-gelatin with respect to penetration depth and % mass retention. Where you start to see variations is when intermediate barriers are placed before the gelatin. Even then, most of the loads are in the same envelope.

You can play around on the ammo test comparison feature on the Winchester LE products page to see some differences.

The bottom line if you pick a round from DocGKR's list, as mentioned above, that works well in your firearm and you can reliably acquire, you'll have chosen wisely.

[Manolito]

Real world balistics is just a small part of the package. If you shoot a .45 but you miss where you want to place the bullet you are not effective. If you come up against one of those rare people that does not know quit you can have a minimum of nine rounds returned even with a good heart shot. The brain stem madula oblangota is a sure immediate collapse regardless of the type of person you shoot.
Having said that proficiency on your weapon of choice is far more important than what bullet you load in it. The cheapest metal jacketed round to the brain stem is a guaranteed stop shot. Just as important is finding cover and surviving long enought to put the bad guy down. There is no one answer and the final one is how will you react to killing another Human.
If you have decided to carry a weapon and have reached the point you are willing to take another life then you should read one very important book in my opinion. This is true for all military, lawenforcement, civillian, and professional. ON KILLING by Lt.Col. Dave Grossman. this book will prepare you for what is to come and explain to you the feelings you will have that you must overcome to pull the trigger or thrust the edged weapon into a human being.
Just my thoughts on a very complex subject and it may help to know that until we studied the reluctance to kill our military had very few shooters and on a battlefield we kept finding hundreds of guns that were never fired. This held true in the civil war up until Viet Nam when the training to overcome these natural reluctance to kill was taught. Viet Nam went up to a 75% return fire rate unheard of before the training. Todays warriors are probably close to 90% but that number is a guess on my part not a scientific study.
The last thing I will offer is when you go to find an instructor it is fine to use an NRA instructor for basic firearm safety and proficciency but when you are ready to pay for a shooting class above the basic level ask one very pertinent question of the instructor. Have you been in an actual live fire fight for your life? Just my opinion on a very complex decision you must make to survive that one day.
Respectfully,
Bill

[Lapietra]

Thanks for the thoughtful replies.

I get that any one of the service calibers will do the job. And I get that any one of the loadings prescribed by the respected professionals on the subject with give good performance. I also get that it is best to shoot and train with what you are and can be proficient with.

But because I am not LE and do not have my ammo chosen for me, I want to use the most optimum load for the caliber I choose for SD.

To me, its like saying any 12ga shotgun will work when you go quail hunting. Yes any will work but #8 shot works best; so thats what I will carry when qual hunting not just any 12ga load.

I currently have many handguns and in many different calibers. I choose the caliber and carry for the purpose at hand. When I hunt I carry 10mm, 357sig or 357mag. For HD I currently choose .40 S&W. When target shooting, plinking and for my sons and wife 9mm.

But I am finding that over time and as I age arthritis has begun to set in and shooting has become a little more detail oriented based on controllability and pain management. Thus if I can identify through examination and understanding of the ballistics a softer shooting more controllable caliber and cartridge that will result in similar performance I want go that route. Thus my original question about understaing ballisitcs and wanting to know if muzzel energy expressed in foot pounds translates to how hard the bullet impacts the target.

[Spirit 1]

"Thus my original question about understaing ballisitcs and wanting to know if muzzel energy expressed in foot pounds translates to how hard the bullet impacts the target."

Yes and no, okay? Some of the correct answer can be visualized in thoughts of your car. On the one hand we have a vehicle the weight of a Volkswagen beetle powered by a 200 hp engine traveling at 45 mph. On the other hand we have a freight train powered by a 200 hp engine traveling at 45 mph. In the case of an impact, which one do you suppose will transfer more relative energy into your vehicle in the moments before it is referred to as what's left of your vehicle? Overall mass in motion is the deciding factor here.

If the speed of the VW sized vehicle is increased that translates into more energy transferred into your vehicle because it requires a longer time to come to a stop. If the VW sized vehicle has a 500 hp engine pushing it instead of 200 hp then again you have more overall energy transfer because the force behind it is greater.

You're dealing with inertial mass. The greater the mass at a given speed the more inertia. The greater the speed of the same mass the more inertia. The more 'power' that is driving a given mass the greater the inertia. It's not a matter of a single factor such as muzzle energy but a combination of all physical properties multiplied.

It seems you're looking for the same thing I was looking for. After much research based on autopsies, wound ballistics and armed encounters I decided a 9mm in standard velocity or +P in a jacketed hollow point was fully adequate for whatever mammals I'm likely to encounter with the exception of bears, though it could potentially do considerable damage there and possibly end the threat, with the deciding factor in all circumstances being shot placement. Within that we may choose a bullet that has higher velocity, or higher velocity plus greater mass to increase the effectiveness.

That's as far as I know. Others may wish to correct my elementary conclusions regarding the science of it because I might have confused myself.

BTW: check out this article on that same excellent linked page, it's chock full of relevant info. It does dispute my assertion that velocity has a large effect and their information is based on hard evidence from ballistic gelatin analysis. I still find it hard to believe, but...

http://www.m4carbine.net/showthread.php?t=98085&page=2

[Lapietra]

Thanks for the input Spirit 1. I guess I am trying to simplify a very complicated issue by translating the ballistics tables incorrectly. I am going to go out this weekend and do some home testing with some of the new 124+p and 127+p+ 9mm I got at the Vallejo gun show last weekend compared to .40 and 357 sig.

180 gr .40 is still manageable for me. 165gr not so much. 125 gr .357 sig is ok with a hogue hand all on my G32 but I cant shoot a lot of any of these calibers in one day. 9mm feels good to shoot and hopefully the hotter loads will compare...

[Spirit 1]

Hope it helps! I found a torrent of opinions on this type of subject with very little evidence or verifiable facts to back up statements & claims.

Once I had sifted through it all I concluded there may be much more powerful loads that may be more effective, but that every single time it's STILL a matter of shot placement that rules the day.

So, we'll practice, practice, practice until the gun becomes an extension of the brain & body, then most likely we're good to go. Have fun while you're at it!