Armscor .45 Auto 230gr JHP gel test and review

@Michael Shannon "The idea that there is a desirable maximum depth of penetration on gel is mainly a sales gimmick"...

Sorry but you couldn't be more wrong about that. The standard 18" maximum penetration exists for a reason. That reason is energy transfer. Any energy your round carries through your target is energy it isn't transferring to your target. Ballistic wounds are just a rupture in a soft body caused by energy transfer. Ergo, a round fired with the same total energy that exits a body has caused less damage to it than one that has come to rest in it, perhaps barring one that manages to exit with just enough joules left to break skin. If all you wanted was to put holes through your target every time no matter what, .17 cal/4.6mm would be the be-all end-all of projectiles.

Moreover, for a perfectly placed shot, wound cavity size isn't terribly relevant. But if you plan to miss at all (i.e. your target isn't holding perfectly still while you set up a nice bench rest shot) you'll want as big a wound track as you can possibly manage. A .17 cal round passing .2 inches from a vital area is just a flesh wound. Even a .22 round stopping in the same spot is fatal. Unless your target is unaware that you're taking aim (in which case you're either a hunter or the bad guy) and you plan to drop a round in the hindbrain, projectile size matters, and beyond a minimum level it matters much more than total penetration depth.

@Mercury There is no such thing as "energy transfer". I'd be interested in where you got this notion.

Example: I have two .45 ACP cartridges- everything is the same except I've downloaded one so that it has 25% of the penetration on gel as the other. The slower one doesn't exit the gel and the faster one does. Please explain how the slower one "transferred" more energy as it came to a rest than the one that was still moving. Which would do more physical damage?

The only way to cause incapacitation from physical causes quickly is to hit (not pass nearby) a vital organ. Deeper penetration will increase the chances of getting to a vital organ. For this reason I think they may be on to something with .22 TCM.

@Michael Shannon Assuming the first round exited with more than 25% of the energy with which it entered, the second round would do more net damage to tissue. This is because when a bullet comes to rest in a soft body, momentum causes further cavitation ahead of it, in an area larger than the projectile itself (look up a ballistics gel test and observe how the "temporary wound track" exceeds the depth of the round itself). This is basic hydrodynamics. However, you've neatly illustrated the more complex point of expanding rounds here: if your round will expand you not only get a larger "permanent" wound cavity, but you also don't have to reduce your round's energy to desired penetration.

And yes, in fact, many "hits" to a vital organ involve passing the projectile near the organ and letting physics do the rest. Again, observe the cavitation effects of a round fired into ballistics gel. A heart or lung within range of that soft body deformation is just as critically damaged as one that has been struck directly. Furthermore, unless your target is very large and/or thick skinned (e.g. moose, bear) 12 to 18 inches in ballistics gelatin tissue analog indicates sufficient penetration in a live target so as to hit a vital organ. More penetration is neither necessary nor desirable. At that point it's much more valuable to have a larger round (whether that's as fired or through expansion) to ensure that what would be a near miss with a smaller round is a critical hit with the round you actually fired.

What you seem to be implying is that a .01 cal ball fired at 42000 fps would be infinitely deadlier than a .45 cal fired at a mere 880 fps, which is patently absurd (both hypothetical rounds have the same muzzle energy). No matter how much energy you put into a projectile that small, it will not transfer enough energy to a target to do any serious damage (unless you somehow got the .01 cal to expand massively, which would be very destructive in a fluid medium such as tissue). Conversely, the .45 round will never penetrate as far as that ludicrously fast-moving .01, but it will do much more damage to anything it passes through or next to in a fluid medium.

What you're describing is actually the ballistics used against hard targets, like armored vehicles. In those cases, the only important thing is that you get through the armor, deformation of the target is actually a negative, and any extra damage you do on the other side is really more of a bonus.

@Mercury I think you're having me on but just in case: when a bullet stops it stops. There is no magic force that continues on from it to destroy tissue. Body tissue is flexible and springs back. It needs to be ripped not pushed to be damaged. I'll repeat: a bullet (a) that goes all the way through a target does more damage than a similar bullet (b) that was on the same track but stopped. It's not possible for it to be otherwise. Bullet B hits everything Bullet A does and more therefore it must do more damage.

With regard to penetration there are all sorts of things that could get in the way of a bullet- drywall, door jams, car doors, clothing, LBE, mags, bone, glass, furniture etc. Bullets also hit targets at different ranges and hence velocities as well as angles. It would be better to see tests done with all of these types of materials in the way and conditions but I understand that's an expensive proposition and we're usually stuck with gel at 10 feet.

BTW your example means if I stick a knitting needle slowly through someone's heart they'll be fine because there was a lack of "energy transfer".

@Michael Shannon Body tissue is flexible to its elastic limit. Beyond that (i.e. when
enough energy is applied) it tears. Tearing causes bleeding. Bleeding causes death. That's energy transfer. Otherwise pistol rounds that reliably pass through a human (5.7mm, .357 Sig) would be deadlier than smaller diameter rounds fired from a rifle (5.56mm and .308, respectively). Furthermore, without energy transfer, FMJ .30 Carbine and .30-06 rounds are exactly the same lethality because they'll both pass through. But they're not, because the .30-06 is traveling faster for its weight, and has more energy. When it drops that energy into a human target, the fluid medium causes stretching (cavitation) that causes tearing in areas the bullet itself never touched (wound track).

Conversely, if you have a tiny enough knitting
needle (a needle for ants), yeah, you can put it right through
someone's heart at any speed you want and as long as it doesn't yaw at all (thereby increasing its forward cross-section proportionally to its length and the degree of yaw) the wound will heal before the target bleeds out. Because it didn't cause any more tissue damage than its minuscule diameter. A teeny tiny wound simply won't bleed that much, even if it's through a "vital" area (exception: spinal nerves, which are so tiny to begin with you couldn't pass a small enough projectile through them to not destroy them.)

Again, referring to the downloaded round example, the "magic force" you're describing is momentum. That's just basic physics. Try pushing some water with your hand and tell me about how it all just stops when you stop moving your hand. Living things are basically just elastic containers for water, and the elastic isn't very
good at being deformed suddenly. This is why, energy being equal, a round coming to rest in a soft body is more dangerous than one that leaves it with some of its energy left. Unless you intend to refute Newton, that energy has to go somewhere, and where that energy goes is into tissue that can't take it. It stretches and tears, making a wound. And, again, this is why expanding ammo is better: you can use more energy to make an even bigger wound with both the projectile and its energy, rather than wasting energy just putting the same hole through a target faster. Up to a point, of course; again, a rifle that carries 50% of its energy out of a target but had 250% of the energy of a given pistol round will have done twice the damage of the pistol round because of, you guessed it, energy transfer. The net energy change over the rate of energy change in the target body is what matters here, not necessarily whether the projectile comes to rest or not.

Regardless, even if it didn't matter if a round passed through or not, even if the only type of damage that mattered was direct hits with the projectile on vital organs, an expanding round would still be superior to a faster, smaller one. Over 18" in gel is still enough to pass through any human-sized target, and a .45 round that expands to 1" on impact can score a hit where a .45 round that stays .45 would pass right by. Even if everything you're saying were true, you're just making a different case for expanding ammo.

Lastly, if you're concerned about ranges outside of "close" and penetration through barriers, you need a rifle, full stop. The right pistol ammo to use for those conditions is "don't." Or if you have to anyway, plan to scare your target rather than hurt it. If you are using a rifle for the purpose, you need a penetrator core in your round, which is a whole different type of ballistics for a whole different set of tactics (again, hard targets and armored vehicles). Pistols exist solely to trade size for firepower, and expanding ammo is a good way to mitigate that disadvantage. It's certainly not worth it to trade expansion for guaranteed overpenetration, as even in the best of circumstances that's a net loss where lethality is concerned.

@Mercury Tell if I've got this right.

There is a force (momentum) that a bullet emits as it stops that will cause more damage than if the bullet continued moving.

Your example with high velocity Spitzer bullets is also illogical. They do more damage than a barrel shaped pistol bullet because they tumble inside the target generally while going through it. Many will break apart and create more than one wound channel. If you reduce their velocity to the point they won't tumble they make far less serious wounds. A number of people have demonstrated this effect by gradually reducing 5.56mm velocity on gel tests.

@FT_Ward That's not even close to what I was saying, no. Given two rounds of the same muzzle energy striking the same target at the same distance, one that comes to rest in a body will do more damage than one that carries most of its energy out of the body. A high velocity round that tumbles is destructive for precisely that reason: it dumps more of its energy into the target as its forward cross-section increases and proportionally increases drag. It's not that you can't cause fatal damage by striking a vital organ directly with the projectile, it's that fatal hits usually don't involve that kind of contact. It's far more often the shockwaves generated in the body by the sudden transfer of energy from a projectile into tissue which flexes it beyond its elastic limits that cause fatal bleeding. It's a question of the net energy change per unit of time, and a round that carries most of its energy out of a target body won't do as much damage as one that rapidly transfers its energy into the body, unless the first round had so much more energy to begin with that it transferred more net energy than the second (i.e. rifle vs pistol). It's not the tumbling itself that makes rifles deadlier, it's the higher muzzle energy plus the sudden increase in drag when it enters a fluid medium that allows it to release more of its energy faster. You're getting caught up on the issue of a round stopping and somehow pulsing out telekinetic energy, when really it's about HOW it stopped, not THAT it stopped that makes the difference in lethality.

You can see this effect by observing the wound track that tumbling rifle rounds leave in ballistics gelatin. Surely you don't think they just jittered around in the block faster than a high-speed camera could even catch a frame of, leaving a wound track orders of magnitude their own size, do you? No, they cause that tearing with hydraulic pressure, by dumping their energy into the block very quickly as their forward cross-section multiplies their drag. You can't get pistol bullets to reliably tumble like that though, so instead you use hollow points. Same result, different method.

@Mercury So you fire the same type of round at a target and hit in exactly the same place and one will go through and the other won't but the one that went through- and ripped more tissue- will cause less damage/ Why would you expect that result?

It's not muzzle energy that matters it's velocity when the target is struck. i.e. after clearing intervening materials. That's why the same bullets do different levels of damage to targets as their velocity drops over range or going through intervening materials.