Quote from: Brad J. Murray;724588I highly recommend this (badly formatted) discussion of skill in combat: http://www.nononsenseselfdefense.com/knifelies.html

I'm quite familiar with that work and have recommended people read it many times. Note however that it refers entirely to knives rather than anything else, and regardless of the claims made I'd much rather face off with a drunken bar room brawler than a Filipino escrimador. YMMV, skill and training are factors in my opinion.

Quote from: Simlasa;724590Which again has me questioning why we choose to make combat into such focus of 'fun', when IRL it isn't any more fun than cancer or car accidents.

Good question for another thread, especially when you consider how slow combat is compared to almost anything else you can do in tabletop yet it gets the commanding share of design space and discussion.

It's all basic physics, they all kill (damage) the exact same way, by hitting a vital organ. Handguns put about as much energy as getting hit with a baseball on someone. The difference in the various weapons are things such as reach (pike) or ease of use (gun, plus it has reach).

Informative link on wound factors: http://www.firearmstactical.com/pdf/fbi-hwfe.pdf

Quote from: Simlasa;724590Which again has me questioning why we choose to make combat into such focus of 'fun', when IRL it isn't any more fun than cancer or car accidents. Something to be avoided. A last resort.
I guess it's back to that wargames ancestry... where again, men die like flies... and not fun for the individual soldier.

Because combat that is larger than life, free of real world consequences and not terribly realistic is fun. Just like action movies are fun. In some games, like investigations or political campaigns, gritty and unfin combat can work well, but for others you want that action style combat.

Quote from: Brander;724561That said, throw an axe, a mace, and a rifle into the mix, and things can quickly become quite different, though armor again matters at least as much, if not more.

Yes, when you start going with more differentiated weapons, it does change; even then, however, I feel it would be good to have the baseline straight.

Quote from: dragoner;724594It's all basic physics, they all kill (damage) the exact same way, by hitting a vital organ. Handguns put about as much energy as getting hit with a baseball on someone. The difference in the various weapons are things such as reach (pike) or ease of use (gun, plus it has reach).

How effectively that damage is delivered was one of the other things I mentioned. Saying that a knife and a bullet deliver damage in the same way is way out there. Even that document you linked makes that clear. And that's without taking into consideration slashing damage from a knife, which again is very different to a bullet and will have different effects on various targets.

So much for basic physics.

The report says it is done in the same way.

Quote from: dragoner;724600The report says it is done in the same way.

Yes, this sounds very like a knife wound:

(1) Penetration. The tissue through which the projectile passes, and which it disrupts or destroys.
(2) Permanent Cavity. The volume of space once occupied by tissue that has been destroyed by the passage of the projectile. This is a function of penetration and the frontal area of the projectile. Quite simply, it is the hole left by the passage of the bullet.
(3) Temporary Cavity. The expansion of the permanent cavity by stretching due to the transfer of kinetic energy during the projectile’s passage.
(4) Fragmentation. Projectile pieces or secondary fragments of bone which are impelled outward from the permanent cavity and may sever muscle tissues, blood vessels, etc., apart from the permanent cavity. Fragmentation is not necessarily present in every projectile wound. It may, or may not, occur and can be considered a secondary effect.

In fact the words knife, knives, stab or stabbing aren't mentioned at all.

Quote from: The Traveller;724597And that's without taking into consideration slashing damage from a knife, which again is very different to a bullet and will have different effects on various targets.

So much for basic physics.

Got to agree -- a razor needs very little KE to injure or kill. KE is only part of a very complex model.

Back to the physics, I found this elsewhere:

"Your question made me curious so I ran the numbers through the physics kinetic energy (ke) formula: ke = 1/2mv^2 formula.

If the knife was thrust at 143 miles per hour, (which is the average speed of a boxer; equivalent to about 64 meters per second) and the knife weighed 0.09 kilograms (which is the mass of the Gerber Guardian Backup knife), the knife would have a kinetic energy of about 185 joules.

The 45 acp with a 200 grain bullet (or .013 kilograms) travels at 1080 feet per second (329 meters per second). This calculates to 702 joules of energy.

Knife = 185 joules
45 acp = 702 joules

The 45 acp is hitting with almost 4 times as much force; and that's if a pro boxer is thrusting the knife. "


I'm not claiming it's accurate, but it sounds about right.

Also, once you have a knife inside your opponent, you are not necessarily done applying KE.

Hydrostatic shock needs to be considered as well when dealing with projectiles.

The energy difference is irrelevant due to conservation of momentum, muzzle velocity vs at range/attenuation, etc (not that I affirm those numbers to be correct, I don't care); the wound is the same.


Penetration is "stabbing".


Slashing with a dagger is unlikely to kill someone in battle.

Quote from: jeff37923;724609Hydrostatic shock needs to be considered as well when dealing with projectiles.

The FBI report cites it as a myth.  /shrug

Quote from: The Traveller;724604Back to the physics, I found this elsewhere:

"Your question made me curious so I ran the numbers through the physics kinetic energy (ke) formula: ke = 1/2mv^2 formula.

If the knife was thrust at 143 miles per hour, (which is the average speed of a boxer; equivalent to about 64 meters per second) and the knife weighed 0.09 kilograms (which is the mass of the Gerber Guardian Backup knife), the knife would have a kinetic energy of about 185 joules.

The 45 acp with a 200 grain bullet (or .013 kilograms) travels at 1080 feet per second (329 meters per second). This calculates to 702 joules of energy.

Knife = 185 joules
45 acp = 702 joules

The 45 acp is hitting with almost 4 times as much force; and that's if a pro boxer is thrusting the knife. "


I'm not claiming it's accurate, but it sounds about right.

My only addition from a physics perspective is that the knife has the additional energy of moving the arm of the wielder, and that energy is part of what would be transferred.  Your math has the knife itself moving in a vacuum, which isn't the case for a melee attack.

Also, from a damage perspective, you can't just use the overall weight of the weapon/projectile, you have to take into account the surface area of the contact and the relative density/resistance of the object/person it's striking.

When you get into the damage as it relates to a person, it becomes more of a concern of WHERE you hit.  Anything with the capability to penetrate flesh to a depth of about 4 inches can kill you dead instantly, with no bone protection.  (this is just about any firearm from .22 FMJ up).  The advantage to larger, heavier rounds is carry distance and bone penetration, which makes it easier to hit those areas (in the sense that larger wound cavities mans you don't have to be as absolutely precise).