.40 Cal home defense ammo

[insatiable ONE]

Originally Posted by agalindo

When talking pistol rounds once the energy used to penetrate and expand is met any "energy" dumped on the target is not going to do any significant wounding. Pistol rounds have neither the velocity or energy to wound via temporary cavity. The shock of the bullet hitting is not going to do damage. The only thing that wounds is the size of the hole the bullet makes and the depth of the hole.
No the .45 ACP has an edge but it's not because of the foot pounds of energy it has it's because it's bigger diameter makes a bigger hole.

Originally Posted by QBiN

However, I really think you're discounting muzzle energy and it's resulting knockdown power. I'm not going to touch the temporary cavity claim. We're not only talking about wounding, but overall effectiveness in the choice of a particular round. So accounting for wounding without taking into account knock-down power is only half the equation

The .45 ACP doesn't have an edge just because of it's wounding effects alone. With a decent hollow-point, it's kinetic energy also delivers a whopping punch to the target causing momentary incapacitation. You think getting shot with a bulletproof vest is a walk in the park? No? Why would that be? Knock-down power is just as critical. It bridges the time before the wounding effects of your rounds kick in and involuntary incapacitation takes the assailant out.

Since ballistic gelatin mimics the properties of muscle tissue, it is the preferred medium for comparing the terminal performance of different expanding ammunition, such as hollow point and soft point bullets. These bullets use the hydraulic pressure of the tissue or gelatin to expand in diameter, limiting penetration and increasing the tissue damage along their path. While the Hague Convention restricts the use of such ammunition in warfare, it is commonly used by police and civilians in defensive weapons, as well as police sniper and hostage-rescue teams, where rapid disabling of the target and minimal risk of overpenetration are required to reduce collateral damage.

Selecting for terminal performance

Further information: Stopping power
The standard medium for testing bullets for performance on tissue is ballistic gelatin. Tests have shown that properly prepared and calibrated 10% (by mass) gelatin at 4 degrees Celsius correlates very closely to observed performance in the muscle tissue of living, anesthetised swine. Performance is generally graded with two factors , the maximum depth of penetration and the size of the cavity formed in the gelatin by the bullet impact. The size of the cavity represents the distance which tissue is thrown radially outward due to "splash." The penetration represents how far into the tissue the bullet will ultimately penetrate.

[1EYEJACK]

Originally Posted by agalindo

Don't get caught up in the "muzzle energy thing" All the bullets listed pass FBI/IWBA protocols. In pistol rounds once the round penetrates the required minimum and expands the excess muzzle energy and velocity will not wound via "energy dump-hydorstatic shock" it will just add to recoil and muzzle blast.

Interesting. I just purchased an XD.40SC and was wondering about choices for SD rounds. I've always used Gold Dots in my .45ACPs so I was thinking that I would use them in my .40S&W also for the reasons you cited.

Nice to have some validation.

[agalindo]

An HP that strikes a soft target imparts the same amount of kinetic energy that is imparted on the shooters hand when it's fired. Well a little less since there is loss once it leaves the barrel. Point is if the energy imparted on the shooter does not knock the shooter down then there's no way it can knock down a human target. The bullet does not gain energy as it travels to the target that too is a scientific fact. I've seen a guy shot at close range with a .45. What happened? His shirt pufffed up at the point of impact. Looked like he had been punched with an invisible fist. He then continued to fight the cops until he was wrestled down by to officers.

[QBiN]

Let me clear one thing up. When I say, "knock-down" power for those getting hung up on that phrase. I don't mean to imply someone will literally fall-over. Rather, I'm talking about quantifiable kinetic force, that component of stopping power, imparted on the target that absolutely has a momentary stunning effect.

[insatiable ONE]

Stopping power is a colloquial term used to describe the ability of a firearm or other weapon to cause a penetrating ballistic injury to a target, human or animal, sufficient to incapacitate the target where it stands.
The term is not a euphemism for lethality. It refers only to a weapon's ability to incapacitate quickly, regardless of whether death ultimately ensues. Some theories of stopping power involve concepts such as "energy transfer" and "hydrostatic shock," although there is disagreement regarding the importance of these effects.
Stopping power is related to the physical properties of the bullet and the effect it has on its target, but the issue is complicated and not easily studied. Critics contend that the importance of "one-shot stop" statistics is overstated, pointing out that most gun encounters do not involve a "shoot once and see how the target reacts" situation.
Stopping is usually caused not by the force of the bullet (especially in the case of handgun and rifle bullets), but by the damaging effects of the bullet, which are typically a loss of blood, and with it, blood pressure. More immediate effects can result when a bullet damages parts of the central nervous system, such as the spine or brain. In response to addressing stopping power issues, the Mozambique Drill was developed to maximize the likelihood of an attacker's quick incapacitation.
A manstopper is a generic term used to describe any combination of firearm and ammunition that can reliably incapacitate, or "stop," a human target immediately. For example, the .45 ACP pistol round and the .357 Magnum revolver round both have firm reputations as "manstoppers." Historically, one type of ammunition has had the specific tradename "Manstopper". Officially known as the Mk III cartridge, these were made to suit the British Webley .455 service revolver in the early 20th century. The ammunition used a 220 grain cylindrical bullet with hemispherical depressions at both ends. The front acted as a hollow point deforming on impact while the base opened to seal the round in the barrel. It was introduced in 1898 for use against "savages,"[citation needed] but fell quickly from favour due to concerns of breaching the Hague Convention's international laws on military ammunition, and was replaced in 1900 by re-issued Mk II pointed-bullet ammunition.
Some sporting arms are also referred to as "stoppers" or "stopping rifles". These powerful arms are often used by game hunters (or their guides) for stopping a suddenly-charging creature, like a buffalo or an elephant.

[Cuda66]

Originally Posted by QBiN

Ok agalindo (and your innumerous quotes). We'll just have to agree to disagree. lol. Hollow points that retain most of their mass impart no kinetic energy. It just evaporates into thin air (gelatin?). I might have drank the same cool-aid if we were talking about frangible rounds or RBCD's. Anyway... Newton is right. That's enough from me.

lol. Takes me back to my Carnegie Mellon days as a TA.

If you want a serious demonstration of just how much "knock down power" a bullet has...shoot some bowling pins.

A bowling pin weighs between 3lb,6oz and 3lb10oz. Let's just take the average and call it three and a half pounds, OK?

Shoot that pin with a .22--about 150ft/lbs energy...you may--may--knock it down, but it won't move far.

Try a 9mm--around 400 ft/lbs--and you'll probably knock it down (with a square hit), and it may roll a few inches...but that's about it. A .40 (about 450ft/lbs) will do about the same, maybe make it skip a couple inches back before falling down.

A .45--500ft/lbs or so--will knock it back about 6" and put it down handily.

So...if those rounds will only move a 3.5lb bowling pin less than a foot...do you honestly think they're gonna knock a 150lb person down?

Kinda defys basic physics, don't it?

[Poink88]

Originally Posted by agalindo

An HP that strikes a soft target imparts the same amount of kinetic energy that is imparted on the shooters hand when it's fired. Well a little less since there is loss once it leaves the barrel. Point is if the energy imparted on the shooter does not knock the shooter down then there's no way it can knock down a human target. The bullet does not gain energy as it travels to the target that too is a scientific fact.

I am no expert but I think your logic is grossly flawed. Should you apply that to rifles like 50 BMG which can shatter concrete walls...the shooter must die instantly if your analogy is accurate.

[Cuda66]

Originally Posted by QBiN

Let me clear one thing up. When I say, "knock-down" power for those getting hung up on that phrase. I don't mean to imply someone will literally fall-over. Rather, I'm talking about quantifiable kinetic force, that component of stopping power, imparted on the target that absolutely has a momentary stunning effect.

An there is no proven correlation between energy dump and your "stunning effect".

There are only two reliable factors in stopping someone with a handgun round.

1--CNS hit. Iffy at best.
2--Exsanguination--which means a deep wound getting to blood bearing structure, preferably a wide-channel one to promote bleed out and have a better chance of hitting those blood vessels.

I strongly recommend you read the previous posted FBI study. These are folks who know what they are talking about, and they make no mention of kinetic energy/stunning power theories.

[Cuda66]

Originally Posted by Poink88

I am no expert but I think your logic is grossly flawed. Should you apply that to rifles like 50 BMG which can shatter concrete walls...the shooter must die instantly if your analogy is accurate.

You can shatter concrete with a sledgehammer--is that fatal to the person swinging the hammer?

[agalindo]

I'm no expert but I did stay at a Holliday Inn.

The bullet form a 50BMG hitting a human would tear him apart because of the temporary cavity created by the bullet. The cavit would be larger than the human this would be cause by the pressure wave created as the bullet traverses the body. It would not knock him back it's been done on myth busters no bullet be it 50bmg or 12ga slug will knock a human sized target back as in the movies.


You really should read the links I posted they explain it much better than I do. If you can find it the Duncan McPherson book will answer all your questions. That along with this link will answer all your questions.

Bullet Penetration: Modeling the Dynamics and the Incapacitation Resulting from Wound Trauma by Duncan MacPherson

Terminal Ballistics