HIGH-TECH-Arrived-Gun Damage

[DouglasCole]

Originally Posted by Fred Brackin

Technically there might be one more. That;s when the size of the temporary cavity exceeds the size of the torso and the target explodes.

Primarily seen in things the size of prairie dogs but I suppose it could be scaled up. A 20mm frangible bullet at over 4000 fps seems about right for a human-sized target.

Fred Brackin

True. this is a subset of "bullet hits inelastic tissue," for those cases where the tissue STARTS elastic but hits the elastic limit. This is also a case where in a ruleset with blow-through, projectiles with more damage than a certain multiple of blow-through have this property, and blow-through no longer applies.

In 3e, it was about 5x the equivalent of average HP for that race in dice: 15d or so vs 3d humans.

[Sadurian Mike]

Originally Posted by DouglasCole

Many firearms enthusiasts do; no scientists do. Read Fackler.

Fackler admits that cavitation occurs, but believes it's effects are over-stated. It is also one piece of research from one organisation(incidently using ballistic gel and not animal tissue) which is attempting to disprove the research of everyone else into the phenomena. I'll remain unconvinced until Fackler's view is supported by more experimentation.

Originally Posted by DouglasCole

Ah...you're using "shock" to mean "bleeding out." You need to be careful here; shock and shock waves are specific technical terms that have very little to do with incapacitation, despite well known but poorly informed assertions otherwise.

Actually, I use shock to mean medical shock, typically systemic shock in the case of ballistic trauma. Shock incapacitates very effectively by cause organ shutdown, and often kills without requiring the victim to lose large amounts of blood.

Originally Posted by DouglasCole

Note that this is quite different from "how bullets punch through solid, homogenous objects," and it is THIS quantity that GURPS damage numbers most accurately reflect. The true (and I hate to use this phrase) 'stopping power' of these weapons can only be assessed once you apply the wound channel modifier, which gurps calls "bullet size modifier."

Well, translating the data into GURPS numbers I'll leave to the writers and houserule what I feel I need to. I'm not a gun-bunny by any means.

Originally Posted by DouglasCole

Neither is the .45ACP, or any other reasonable self-defense or assault rifle cartridge.

I'm not asserting it is, I'm pointing out that calibre alone is not the measure of a round's effectiveness.

Originally Posted by DouglasCole

Comparing a .223 and a .45ACP with a full power battle rifle isn't exactly proper. It's got twice the energy, three times the mass, and a larger cross section than the 5.56x45mm NATO. No one would expect anything less than this round being more effective than the 5.56mm round.

Exactly, a 7.62mm round is more effective than an 11.4mm round (.45"). Therefore, calibre alone is not the issue, and muzzle velocity plays a role, which is what I was trying to show.

Originally Posted by DouglasCole

He was quoting the .50AE, not the .50BMG. The .50AE from the Desert Eagle gun does about 4d in GURPS (the ,500S&W about 6d) which favorably compares to musket balls in penetration, although the spherical lead musket ball probably qualifies for an armor divisor of about (0.8).

Actually, a musket ball is usually of larger calibre than .50, the Brown Bess quoted by Icelander being .75". A calibre of .50 would be more suited to a small pistol of the age, which naturally equates to a lower muzzle velocity. In any case, if we are trying to stay like-for-like (which I assume you are, given your comments about the 5.56mm, .45ACP and 7.62mm NATO rounds above), we need to be looking at handguns only and not comparing longarms to handguns. That's why I mentioned the .50 (referring actually to the likes of the Barrett rather than the M2 Browning) in relation to comparison to Icelander's .50 musketball.

Not having my books, I don't know for sure, but is the flintlock pistol statted as being as powerful as the Desert Eagle? I think it unlikely somehow.

[DouglasCole]

Originally Posted by Sadurian Mike

Fackler admits that cavitation occurs, but believes it's effects are over-stated.

This misses the point. Not only does he "admit" that cavitation occurs, he gives four mechanisms by which it can be the primary wounding mechanism (hitting inelastic tissue; leveraging fragmentation effects; hitting elastic tissue that reaches its inelastic limit; having the tissue pushed aside by the temp cavity impinge on major nerve centers). However, none of these are certain; the only thing that IS certain is the permanent wound cavity.

It is also one piece of research from one organisation(incidently using ballistic gel and not animal tissue) which is attempting to disprove the research of everyone else into the phenomena. I'll remain unconvinced until Fackler's view is supported by more experimentation.

I think you need to do more reading; every piece of responsible science and forensic pathology I've seen backs up Fackler's view. The only people pushing other points are marketing/sales types, or those trying to sell gun magazines. The fact that Fackler was the president of the professional society for wound ballisticians, and wrote peer-reviewed papers critiqued by law enforcement, medical, and military folks speaks a lot to its credibilty.

Actually, I use shock to mean medical shock, typically systemic shock in the case of ballistic trauma. Shock incapacitates very effectively by cause organ shutdown, and often kills without requiring the victim to lose large amounts of blood.

This sounds highly anecdotal. It also sounds wrong. Do you have citations to back it up? Gunshots wounds, other than CNS hits and major blood loss, are HIGHLY survivable, especially with modern medical treatment and often without it.

That's why I mentioned the .50 (referring actually to the likes of the Barrett rather than the M2 Browning) in relation to comparison to Icelander's .50 musketball.

the Barrett fires the same round as the M2 Browning. Icelander was comparing a large, relatively slow musket ball with a modern version of that, a large, relatively slow pistol cartridge.

[DouglasCole]

Before this gets too far out of hand:

1. Sadurian Mike's point that the factor putting one GURPS pistol cartridge over another was muzzle velocity is basically right...it's a factor proportional to the sqrt of the round's kinetic energy divided by its cross section, multiplied by a constant that happens to be a factor of cross section. My own empirical work using published stats vs actual penetration numbers for bullets comes out as sqrt (KE^1.04) divided by sqrt (Xsection^0.314) x a constant.

So when/if people complain that the .40S&W is "better" than the .45ACP or .45GAP, this is because the energy of the.40 is higher, and the cross section is lower, than the .45ACP. The .40 does earn its point or two of extra penetration. Where GURPS doesn't model reality as well, is that there are only two levels of ouch after penetration is figured (in the range of interest here): pi and pi+.

So we're left with a dilemma: do we give .40S&W 2d+2 pi (making it exactly the same as a 9mm, but with heavier ammo and fewer shots in the mag), or do we give it 2d+2 pi+, making it so clearly superior to the .45ACP that no one would carry anything else (esp if it's as deterministic as GURPS makes it look). Many common .40S&W guns in High Tech don't have the 5" barrel needed to get 2d+2 out of the .40, though, and many are 2d+1 pi+, which again thanks to granularity is still better than the .45ACP.

The decision was made a LONG time ago to put the boundary at 10mm/.40 for pi to pi+...so the game turns the .40S&W into an uber-cartridge and the 10mm Auto even more so. Without a level of granularity that would be hard to achieve (say, +25% damage for the .40 and +50 damage for the .45) without howls of protest from everyone who doesn't want to break out a calculator during play, something has to give.

2. What led us down the argumentation path is the assertion that "ballistic shock" is a primary mechanism of incapacitation for bullets. It is not. Bullets cause CNS damage, destroy important organs and cause bleeding, or cause structural damage that lead to pain and immobility. To Fred and Anthony's points, they also scare the bejeezus out of people and occasionally cause spectacular versions of "destroy organs and cause structural damage." The medical shock is a secondary effect. What MOST people in this field making (bad) assertions mean by 'shock' is a shock WAVE, which has been asserted (not by anyone in this thread, at least not yet) that a hit to the hand can cause a shock wave to travel through the arm and cause incapacitation or death. I'm not kidding. So, when people start talking "ballistic shock," other people start not taking them seriously. Medical shock is a second order effect of organ damage and bleeding; bullets don't cause it directly. Clearly, if somone goes into shock, they're likely incapacitated. But the best way to have that happen is to punch really big holes in important blood vessels or blood-bearing organs like the heart and liver.

3. The diversion into muskets and large pistol cartridges was Icelander pointing out that "big ass hole" is most easily accomplished by throwing a "big ass bullet." He made a (valid) analogy between older muskets and rifles, firing .50 to .80 caliber lead balls at low velocity, to modern .50AE (or .50GI, or .500S&W, or...) bullets which have the same basic approach (big, heavy and large wounding cross section). These projectiles are BOTH effective manstoppers, and the theory (all other things being equal, make a big hole) is not only supported by experience, but it's also a direct inference from the work of responsible wound ballisticians.

[Sadurian Mike]

Originally Posted by DouglasCole

This misses the point. Not only does he "admit" that cavitation occurs, he gives four mechanisms by which it can be the primary wounding mechanism (hitting inelastic tissue; leveraging fragmentation effects; hitting elastic tissue that reaches its inelastic limit; having the tissue pushed aside by the temp cavity impinge on major nerve centers). However, none of these are certain; the only thing that IS certain is the permanent wound cavity.

I think you need to do more reading; every piece of responsible science and forensic pathology I've seen backs up Fackler's view. The only people pushing other points are marketing/sales types, or those trying to sell gun magazines. The fact that Fackler was the president of the professional society for wound ballisticians, and wrote peer-reviewed papers critiqued by law enforcement, medical, and military folks speaks a lot to its credibilty.

Well none of the medical papers is trying to sell guns, and cavitation effects are documented in them. A quick Google brings up the first result of "ballistic cavitation" from a student BMJ paper overseen by Kirsten Jones, the consultant in emergency medicine at Frenchay Hospital in Bristol. That was the first result that appeared, it is is from a reliable medical source, and it describes cavitation (whilst mentioning that some ballistic research doubts its effects). That makes at least two sides to the story so I will remain unconvinced until further research is done.

Originally Posted by DouglasCole

This sounds highly anecdotal. It also sounds wrong. Do you have citations to back it up? Gunshots wounds, other than CNS hits and major blood loss, are HIGHLY survivable, especially with modern medical treatment and often without it.

Systemic shock is anecdotal and wrong?! Now who needs to do more research! You want cites? Try typing "systemic shock" into Google. Alternatively, get hold of some medical publications or talk to anyone with medical training.

Originally Posted by DouglasCole

the Barrett fires the same round as the M2 Browning. Icelander was comparing a large, relatively slow musket ball with a modern version of that, a large, relatively slow pistol cartridge.

A modern pistol is not the equivalent of a musket, and should not be used to compare calibres and muzzle velocities. To show that calibre and muzzle velocity are, or are not, important in determining round effectiveness, you need to use the same calibre at different muzzle velocities, or the same muzzle velocity with different calibres.

Trying to compare a smoothbore longarm musketball to a modern low velocity pistol of the same calibre is pretty worthless, because you are trying to go out of your way to find something that matches both calibre and Mv (though I'm not convinced a musket and .45 pistol are equivalent Mvs in any case, and they are certainly not the same calibre). To test the calibre/Mv variable, you need a low velocity (the .50" musket) and high velocity (the .50 Barrett) example of the same calibre. If the effectiveness stays the same then obviously Mv plays no part. I cannot imagine that being the case for a second.

[Kyle Aaron]

Originally Posted by Anthony

You left out the most important: psychological. To quote:
[snip]
This suggests a realistic (if minor) advantage to a weapon with a big, obvious muzzle flash.

"Hah! I rolled 7 - I dodged the bullets!"
"You've never been shot at before. It's pretty scary. Make a Fright Check."
"I wouldn't be scared of bullets, I'm a PC!"
"Got Unfazeable? A level or two of Fearless? If so, add them to your Fright Check."

"Okay, you got hit. The round hits like you like a sledgehammer in your gut for -", dice roll, "6 damage. No armour? Okay, that's 9 delivered damage. That's a major wound, so roll HT to stay up."
"Rolled 10. Still up!"
"You've never been shot before, make a Fright Check."
"But I can stay up, why would I be afraid?"
"Being shot is a scary experience, now make your roll."

Realistically, the exact calibre is not terribly important. Being shot is always bad. That's because it hurts, it can break bones which cripples you for months, and a wound which you can walk with, you might bleed to death from it. And unless you've very good medical care - which the average PC doesn't - the chances of infection are pretty significant.

In game terms, to get this realism, you'd use Fright Checks for first firefights and first experience of being shot, the bleeding optional rules (I just use them for any penetrating "major wound"), and the infection optional rules. You'd then find that 2d vs 2d+2 doesn't make much difference.

To avoid Fright Checks, it's worth remembering an invention of our own Luther - the Combat Veteran [5] trait. That's Combat Reflexes with the +1 to Fast Draw and +1 to active defences removed. Basically, you've been shot at before, and are unlikely to panic under fire.

[DouglasCole]

Originally Posted by Sadurian Mike

Systemic shock is anecdotal and wrong?! Now who needs to do more research! You want cites? Try typing "systemic shock" into Google. Alternatively, get hold of some medical publications or talk to anyone with medical training.

How about my father in law, physician for 45 years, and medical director (meaning he's primarily a statistics master these days?) I never claimed systemic shock doesn't exist; it certainly does. But it's also not the primary factor in incapacitation, although it can be the result of said primary factors.

People get shot, they bleed a lot or their metabolism gets whacked due to organ destruction (both of which depend greatly on shot placement and target conformation, meaning they're really hard to control for). They may then go into shock and die if left alone and the wound is severe enough; they may bleed out; they may get better. But the point of a bullet isn't to cause "systemic shock." If you're lucky, you hit the brain or spine, there, "shock" isn't really an issue - you just drop right then. Agreed?

The second best way to surely incapacitate someone is to reduce the available blood volume to brain and muscles. This effect I believe is called hypovolemic shock, basically medical speak for low blood volume. But shock is the secondary effect; the causal agent is bleeding like the proverbial suck pig.

A modern pistol is not the equivalent of a musket, and should not be used to compare calibres and muzzle velocities. To show that calibre and muzzle velocity are, or are not, important in determining round effectiveness, you need to use the same calibre at different muzzle velocities, or the same muzzle velocity with different calibres.

OK. How about the .22LR vs the 5.56x45mm NATO? I honestly don't understand your point here. If you really want to look at the effects of velocity, look at the 5.56x45mm round at 50m, 200m, and 500m. The wound channels are roughly (a) gross and spectacular, as fragmentation while the projectile is in the body causes the temp cavity to actually mean something, (b) bad but not nearly as bad as (a), as the bullet tends to break in half at the cannelure and make two wound tracks rather than one, and (c) roughly the same severity as a .22LR round, which is to say "hardly at all unless you hit somehthing really important."

No one's arguing that both energy and caliber aren't important.

Trying to compare a smoothbore longarm musketball to a modern low velocity pistol of the same calibre is pretty worthless, because you are trying to go out of your way to find something that matches both calibre and Mv (though I'm not convinced a musket and .45 pistol are equivalent Mvs in any case, and they are certainly not the same calibre).

Well, you could look it up. The Brown Bess fired a 545grain projectile at about 1000 feet per second. This puts it in almost exactly the same velocity class as many, if not most, handgun rounds of modern manufacture. However, it obviously throws a MUCH larger projectile, twice the mass of the .45ACP. The velocity of the .45ACP out of the M1911 pistol is usually about 245m/s (805fps).

Saying that the musket is in the same class of projectile as some of the larger handguns out there probably isn't too far wrong. The .50AE that Icelander referred to fires about a 300gr bullet (.55% less mass) at about 1400fps (40% more velocity). So energetically, there is less then 5% difference between the two. This means the .50AE will penetrate better than the Bess, as the cross section of the pistol is smaller, and the projectile shape more efficient at punching through things. The wound cavity of the lead ball will obviously be larger, and if it transects the torso, will produce higher probabilities of a killing wound. In GURPS terms, my calcs give the Brown Bess 3d+2 pi++, and the .50AE 4d pi+.

To test the calibre/Mv variable, you need a low velocity (the .50" musket) and high velocity (the .50 Barrett) example of the same calibre. If the effectiveness stays the same then obviously Mv plays no part. I cannot imagine that being the case for a second.

Again, no one is claiming that muzzle velocity plays no part; quite the oppostite.

The .50BMG round fired from the Barett, though, is wildly out of the class of the musket. The projectile is heavier (660gr for the .50BMG round), shaped differently (an ogive with a 4:1 aspect ratio, compared to a sphere), and faster (890m/s vs about 305m/s). This round has been known to blow humans into two pieces (video evidence from both Iraq wars).

[Anthony]

Originally Posted by Sadurian Mike

Actually, I use shock to mean medical shock, typically systemic shock in the case of ballistic trauma. Shock incapacitates very effectively by cause organ shutdown, and often kills without requiring the victim to lose large amounts of blood.

Remember, internal bleeding is blood loss for these purposes. Shock is, specifically, a medical condition caused by insufficient blood flow. The usual reason for a wound to cause this, on the short term, is bleeding (either blood loss, or a sudden loss of blood pressure due to severe bleeding).

Organ failure is reasonably likely to result in septic shock, but that won't generally happen in the time frame of combat.

[DouglasCole]

Originally Posted by Sadurian Mike

A quick Google brings up the first result of "ballistic cavitation" from a student BMJ paper overseen by Kirsten Jones, the consultant in emergency medicine at Frenchay Hospital in Bristol. That was the first result that appeared, it is is from a reliable medical source, and it describes cavitation (whilst mentioning that some ballistic research doubts its effects). That makes at least two sides to the story so I will remain unconvinced until further research is done.

So, I read the document. Some observations:

They don't know much about guns, and repeat some things that could be easily checked:

Originally Posted by Omar Mukhtar and Kirsten Jones

Rifled firearms

Handguns and rifles are rifled firearms. In both, the barrel of the weapon is grooved, causing the bullet to twist when fired; the shooter experiences less recoil and can take a more accurate shot. The range (the distance between the muzzle of the weapon and the victim) can be determined by close examination of the entrance wound.
Smooth bore firearms

Smooth bore firearms--the commonest example of which is a shotgun--are weapons in which the barrel is simply a tube. The cartridge for smooth bore firearms is also quite distinctive--releasing between seven hundred and six hundred pellets depending on the type of shotgun.

some mistakes:

Rifles don't reduce recoil; rifling has little if anything to do with recoil

The range can only be distinguished in three categories: contact wounds, close range wounds (determined by the presence of gunpowder burns on the skin or clothes), and 'everything longer range than the first two.' Source: Di Maio "Gunshot Wounds."

The cartridge of a shotgun will release between SEVEN and six hundred pellets depending on the type of shotgun. The cartridge distinctiveness is irrelevant to the treatment of the wound, however, as it won't be around. Only the pellets remain.

The fact that they make such elementary mistakes tells me there's a chance they're repeating common medical lore about gunshot wounds while not being up to date on the most recent publications and findings. My father-in-law, the medical professional to which you referred me, will say that more than half of medicine as practiced even in the best care facilities in the world, is history-based and not evidence-based.

Originally Posted by Mukhtar and Jones

The wounding capacity of a bullet is related to the kinetic energy transferred from the bullet to the body, the "flight" and type of bullet and the tissues injured. A common misconception is that the mass of a bullet is more important than its velocity in determining its kinetic energy, but this is not the case, as shown by the formula KE=½2mv2.

Hard to know where to start with this one. The wounding capabilty of projectiles isn't necessarily related to the energy content. Sadurian Mike pointed out, quite corectly, that arrows usually of less than 200J, often less than 100J, kill people just fine, with low KE. There are also many ways to expend KE in the body while doing very little, and ways to expend very little KE in the body while killing a person deader than hell.

No one with better than a 9th grade education has a misconception that mass is more important than velocity in influencing Kinetic Energy. What there is much debate about is if momentum or kinetic energy is more important in being correlated with effective cartridges. The "muzzle velocity" school typically goes for the all KE, all the time (light bullets fired very fast) method; the "cannonball" school is primarily concerned with momentum, "power factor," or just hole size.

In reality, a combination of both is required. You need enough penetration to punch through obstacles, including the structural protection of the body itself, and carry a sufficiently large wound to the critical organs.

Anyway, that they would assert that many people misperceive that E = 1/2 M V^2 rather than address the real debate as to whether energy or momentum is the deciding factor doesn't help their credibility here.

Originally Posted by Mukhtar and Jones

Another physical factor which must be considered is the angle of yaw at impact. (Yaw is the deviation of a bullet from the horizontal axis.)

Just when I thought they were on to something, they swing and miss. The important thing about yaw isn't the angle on impact...it's the yaw within the body. This is a common and understandable problem, for two reasons:

1) initial description of yaw and precession in bullets vastly exaggerated the degree of yaw in a bullet's flight for emphasis; many read this and took it literally

2) in some well publicised issues with lightweight, high velocity cartridges - and really we're talking the M16 here, they weren't spun fast enough to keep 'em stable. So they would ocasionally hit sideways in testing and in combat. Subsequent designs fixed this.

So the principle issue that physicians will face with bullet yaw is INTERNAL yaw, not yaw at the moment of impact.

Originally Posted by Mukhtar and Jones

Cavitation is widely considered to be the most important mechanism of injury in high velocity gunshot wounds although some ballistics experts doubt its existence.

Sweeping and, more importantly, wrong. The debate is over the importance of the temporary cavity, not whether it exists. In making such a statement, they are either trying to minimize the weight of evidence on the other side without dealing with it, or ignorant of the differences. Neither is a terribly responsible pathway. I dispute the assertion that cavitation is considered (generally) the most important wounding mechanisms, and I strenuously object (well, as much as anyone needs to strenuously object to anything in a discussion on an internet chat forum) to the characterization about disbelief over the existance of temporary cavity. Fackler points to it extensively, and its a well known phenomenon. However, if Dr Fackler won't do, here's Dr Vincent DiMaio, Chief Medical Examiner of Bexar County in San Antonio, Texas, and affiliated with the Southwestern Institute of Forensic Sciences in Dallas, has this to say in an appendix to his book on gunshot wounds: "...the temporary cavity phenomena is of little or no significance in wounding when dealing with handgun bullets." He also notes "Aside from areas in the central nervous system, while a billet may rapid incapacitation, there is no guarantee that it will produce instant incapacitation. This is because in these other areas incapacitation is produced indirectly by depriving the brain of blood and oxygen."

Originally Posted by Mukhtar and Jones

Given the subatmospheric pressure in the cavity, debris and organisms are sucked in--causing supra-infection.

This I've never heard before; it would be interesting if true, but based on the errors earlier in the document, why should I take it at face value? Most of the time, I've heard of debris being PUSHED into the wound, rather than sucked in.

The point of the above was that the paper cited above as "the first one that came up" isn't very good. It's not sourced at all, makes assertions that can be highly questionable at best, or outright wrong in many places. They dismiss their opponents points of view in two places (misconceptions about KE; that ballisticians disbelieve the existance, rather than the importance, of temporary cavity) that are falsely disparaging. They also seem to have a very limited scope of knowledge about the weapons that produce the wounds they will be treating. I don't have much of a problem with that, so long as they refrain from making commentary about it...which they do NOT do, offering up misconceptions and inaccuracies that two minutes of Google would have prevented. In fact, that this paper is totally unsourced is its biggest flaw, especially when offering up synopses of positions that they claim are "widely held."

There's a joke in the scientific publishing world: "It is widely believed..." means "I believe." Seems to me that this paper makes that error, not to mention others. It is a common failing of papers in this field; the conventional wisdom is strong.

[Rupert]

Originally Posted by DouglasCole

Guidelines for bonuses to Intimidation and whatnot would be welcome, but not really appropriate to a discussion of whether the stats of the various GURPS weapons are either an exact match, a playable abstraction with some regrettable artifacts, or flat wrong.

Just give a bonus based on the absolute value of Bulk, with adjustment for pistol vs longarm, and size of the hole in the muzzle. The Desert Eagle in .50 AE is probably the gold standard for handguns, and the double-barrel shotgun for longarms.