Several 9mm questions

[nahfuten]

This is a list of 9mm statements that I've read. Please correct me or offer advice.

1. 115gr is usually fastest, 124 is in the middle, and 147gr is slowest.
2. Faster loads penetrate less, i.e. 115 penetrates less than 124 which penetrates less than 147.
3. Slower loads have more "stopping power", whatever that is presumed to mean.
4. Hollow point, in any weight, makes a bigger entrance wound
5. Hollow point penetrates less than a comparable weight round nose projectile
6. Hollow point is safer for bystanders and neighbors due to lower penetration
7. Hydra shok hollow points still penetrates a lot due to the point in the center

Additionally, where do +P loads fit into this? Most of the +P loads I see are 115gr. Does that just make it faster? Does it penetrate less than a standard pressure 115gr? Why do I want +P?

 

[boman]

All those statements(1-7) are pretty much right on.
When you get into the +p questions you cloud the issues a little bit. A +p round is faster and therefore should have better penetration but you still have to compare apples to apples and a +p 115 may not penetrate as much as a 147 regular load for instance. I say may because I haven't compared the penetration ballistics.

Steve

 

[JohnP82]

hollow points are meant to be safer as long as you hit what you are aiming at. they are less likely to over penetrate as ball ammo can do, especially in 9mm. as many times a shot can go through and through both in a badguy or a wall. they also leave a pretty nasty wound cavity in the badguy since they are designed to expand although the initial entrance wound may not differ too much as you asked. and no matter how many people want to tell you the 9mm is not a good manstopper no matter what load of 9mm i bet none of them would want to get hit with one. 9mm is a good round.

also, if you are looking into +p ammo make sure your gun is rated for it before you try it.

 

[lawrra]

hollow points are meant to be safer as long as you hit what you are aiming at. they are less likely to over penetrate as ball ammo can do, especially in 9mm. as many times a shot can go through and through both in a badguy or a wall. they also leave a pretty nasty wound cavity in the badguy since they are designed to expand although the initial entrance wound may not differ too much as you asked. and no matter how many people want to tell you the 9mm is not a good manstopper no matter what load of 9mm i bet none of them would want to get hit with one. 9mm is a good round.

also, if you are looking into +p ammo make sure your gun is rated for it before you try it.

Any of these pistols are fine with +p, since they are NATO certified:
glock 17/19
sig sauer 228/226
browning hi-power
beretta M9
CZ P-01

 

[SKSnut]

#3 slower loads have more stopping power- Is this true?????

 

[Indy_Guy_77]

"Stopping Power" is almost a conflict in terms...

It's a rather mythical concept that depends on several different factors that change with each situation and scenario.

You have one "camp" of people who say that light and fast = best stopping power

Other say heavy and slow = best stopping power

Then there are the heavy and fast people...

Then there are the "won't work for self defense because it's too small" people...

Then there are the shot placement people...

Don't buy into any of the hype about "stopping power".

God forbid that you're ever in a self defense situation in which you must use a firearm to defend yourself, getting a round (or rounds) on target is the. most. important. thing.

-J-

 

[bigdaddy1427]

This could open up a big debate, but slower does not equal more stopping power. Take a softball or baseball, throw it underhand at somebody as slow as you can. Does it hurt or stop you? Take the same object and throw it at somebody has hard as you can. Does it hurt more? Does it have a better chance of hurting somebody?
If you shoot somebody with a 230 grain bullet at 700 FPS, and have the same bullet at 1200 FPS, you get more stopping power. What do you think the purpose of +P loads is? Get more velocity, and stopping power, from the same load.

 

[Mr. Habib]

This is a list of 9mm statements that I've read. Please correct me or offer advice.

1. 115gr is usually fastest, 124 is in the middle, and 147gr is slowest.
2. Faster loads penetrate less, i.e. 115 penetrates less than 124 which penetrates less than 147.
3. Slower loads have more "stopping power", whatever that is presumed to mean.
4. Hollow point, in any weight, makes a bigger entrance wound
5. Hollow point penetrates less than a comparable weight round nose projectile
6. Hollow point is safer for bystanders and neighbors due to lower penetration
7. Hydra shok hollow points still penetrates a lot due to the point in the center

Additionally, where do +P loads fit into this? Most of the +P loads I see are 115gr. Does that just make it faster? Does it penetrate less than a standard pressure 115gr? Why do I want +P?

1. Generally true
2.Not always true. For example a 115 gr FMJ may penetrate more then a slower 147 gr JHP because the HP may expand and slow down quicker.
3. 'Stopping power' is a myth. A .22 short in the brain stem has more 'stopping power' then a 600 Nitro Express to the big toe. Shot placement, mind set of the target, and many other variables are more important than bullet weight.
4.Maybe. Hollow points are better only if they expand. Many times they fill up with clothing, tissue, etc. and mimic a ball round. When they do expand, it's usually inside the target, so the entrance wound will be about the same size. The exit wound, if any, may be larger.
5.Typically true, if it expands, see #4 above.
6.Generally true, but depends on many variables.
7.The post in the cavity of the Hydra Shok is to help promote reliable expansion. It isn't there for penetration.
+P just means that round is loaded to a pressure higher then the SAAMI spec for that cartridge. Typically, it's about 8-10% hotter. In theory this should give better performance, if the bullet is designed to work at that velocity.

 

[GarandMD]

These are all often debated questions and multiple studies abound to help clarify or muddy the debate. I agree that the whole idea of "stopping power" is questionable. I have found the following site offers an interesting comparison of several types of rounds and the data is presumably from actual shootings. Shot placement is not discussed in the tables. I think the most important thing to note is the sometimes minimal difference between the different rounds. To me, the most important thing is practice and getting the round on target.

Handloads.Com - Stopping Power?

 

[Cygnus]

Any of these pistols are fine with +p, since they are NATO certified:
glock 17/19
sig sauer 228/226
browning hi-power
beretta M9
CZ P-01

Add Ruger p95's to that list. They actually say +p+ in the manual.
Likley all their P series pistols.

 

[cosermann]

Many of the whys and wherefores of how bullets act on a target in terms of penetration are fairly well understood. It's physics. It's also why most modern duty loads are engineered to perform surprisingly similarly regardless of caliber. However, how this translates to the question of "stopping power" or terminal effect on a biological target, I'll leave up to you to make up your own mind.

In the context of handgun cartridges such as 9mm:

To make it simple penetration depends on three key factors; velocity, sectional density, and rate of expansion. With all other factors held constant (and assuming a projectile holds together):

* higher velocity projectiles penetrate more,
* projectiles of higher sectional density penetrate more,
* projectiles that do not expand, or that expand more slowly, or that expand less, penetrate more than projectiles that expand faster, or that expand more.

1. Generally/usually true within a given pressure level. However, if you start comparing +p of heavier weight bullets (like 124 gr +p) to std pressure loads of lower weight bullets (like std pressure 115 gr), things get fuzzier.

2. Not necessarily true, but sometimes/often true within a given bullet weight. You’re changing two variables in this statement: velocity and bullet weight. Heavier bullets have greater sectional density and are more penetrative at any given velocity (all other factors being equal). This greater ability to penetrate even trumps the higher velocity of lighter bullets (sometimes/usually). Example: at a given speed, would you rather get hit with a volley ball or a bowling ball (roughly the same “caliber”, different weight)? How much faster would the volleyball have to be thrown before it's a wash? This is often true for particular bullets that are loaded to higher velocities (but aren’t changed in any way to accommodate for the velocity increase), because the bullet expands faster at the increased velocity. For example, a 115 gr bullet, driven at +p velocities may penetrate less if it expands significantly faster at the higher velocity. OTOH, a 115 gr bullet designed to deliver the same expansion profile of its slower counterpart should penetrate more due to the higher velocity.

3. Not necessarily. Whatever that means.

4. Why would a hollowpoint, that does not expand until it’s inside, make a different size entrance wound? Think about it. At least 1 study shows that HP entrance wounds can be distinguished, by careful examination, from wounds caused by solids, but it has nothing to do with the size of the entrance wound.

5. Generally true. The expansion of a hollowpoint bullet has a “parachute” braking effect of sorts that reduces penetration as compared to nonexpanding bullets of the same weight/velocity/caliber.

6. Considering that most rounds fired in defensive situations don’t even hit the target, I think this is overrated. If there’s nothing between the muzzle and a bystander, it matters little whether misses are HP bullets or solids. There may be some benefit if a barrier is between the muzzle and the bystander.

7. The older Hydrashok bullets tend to penetrate more because they often fail to expand, and when they do, they expand less, for caliber, than more modern designs – thus less “parachute” effect = more penetration. Simple. The “point” has little to do with it. Seems to me I saw a study that tested this some time ago, by firing Hydrashoks that had had the point removed. Not much effect, IIRC.

Additionally, where do +P loads fit into this? Most of the +P loads I see are 115gr. Does that just make it faster? Does it penetrate less than a standard pressure 115gr? Why do I want +P?

+p loads exist for three primary reasons, imo:
1) to satisfy those who believe energy and shock are important,
2) to get some bullet designs to expand more reliably that wouldn’t otherwise do so at lower velocities,
2) to get lighter bullets to penetrate more (like their heavier counterparts). All else being equal +p makes things faster (although out of a shorter barrel, you may just be keeping up with what is delivered out of a longer barrel, but that wouldn’t be holding all the variables equal would it?).

If you can get the penetration and expansion characteristics you want with a heavier, standard pressure bullet, there's little reason to go with a +p load. Personally, I prefer heavy for caliber bullets in standard pressure loadings. Easier on me and the gun. Less muzzle blast. Faster follow-up shots. Does the job.

The 9mm can perform adequately with a carefully selected, well designed load.

Best Choices for Self Defense Ammo
CALIBERS -- Why the Nine?  Advocating the 9x19mm

 

[Turn Key]

Good information cosermann !

Rep'ed


TK
https://www.indianagunowners.com/forums/members/cosermann.html

 

[Hoosier]

The theory is the shooter wants the target to absorb the maximum energy from being hit by a projectile. The faster projectile may exit the target and there is energy lost. A bigger slower projectile tends to remain in the target and therefore more energy is absorbed. However, the slower projectile needs enough energy to develop a large wound channel, penetrate far in to the target without exiting.
Hollow points or soft lead tend to "mushroom" more and make a larger wound channel. The larger channel has the potential to damage more of vital areas of the target and terminate the target.
Hoosier

 

[jmiller676]

[ame=http://www.youtube.com/watch?v=uhXSTqV0CT4]YouTube - Hornady Critical Defense ammunition[/ame]

 

[cosermann]

The theory is the shooter wants the target to absorb the maximum energy from being hit by a projectile.

This is by no means a universally accepted theory (especially at handgun velocities). There's a lot going on with terminal ballistics. Energy is only one factor.

Further reading:
The Myth of Energy Transfer
MagSafe, Glaser, Quik-Shok, BeeSafe -- Prefragmented Bullets: Dangerously Inadequate for Personal Defense
http://www.firearmstactical.com/pdf/fbi-hwfe.pdf

 

[Hoosier]

"This is by no means a universally accepted theory (especially at handgun velocities). There's a lot going on with terminal ballistics. Energy is only one factor."

What are the other factors?
Indiana

 

[cosermann]

Reading the rest of this thread and the posted links should give you some idea.

 

[Hoosier]

I majored in Physics in College and it still gets back to energy.

 

[cosermann]

Spoken like a true physics major.

If the energy isn't converted into useful work, it means nothing in this context. Bullet design, sectional density, etc. all affect how this conversion happens.

Read the thread and the links and you'll start to gain some appreciation for how this works within the context of terminal ballistic effects on biological targets.

Examples:
http://www.firearmstactical.com/images/Wound%20Profiles/357%20Magnum%20Glaser.jpg
http://www.firearmstactical.com/images/Wound Profiles/357 Magnum.jpg

The first represents 767 joules badly converted into useful work.
The second represents 732 joules more effectively converted into useful work.

Wound Ballistics, Ballistic Injury, Stopping Power, Gunshot Wounds

I don't want to give the impression that everyone is a "Facklerite" either. A good approach, imo, is to combine the findings of wound ballisticians, with hunting experience, and historical performance looking for a convergence of data to help identify the best loads.

 

[Hoosier]

I am shocked...the other major was in math.lol