I was wondering about what is most important for killing power when it comes to blunt weapons (Like a stone from a sling or slingshot)

For penetrating bullets energy is generally considered the important factor in killing power. The argumentation for this could be that the penetration requires work to be performed by the bullet. (This favors a small high-velocity bullet over a large lower-velocity one)

Is it the same for a stone that relies on bludgeon effect? Or is momentum more important here, since momentum is what accelerates the hit object ? (This would favor a large but slower stone compared to a small fast stone)

There are other threads here that adress this topic at length.  Look them up.  Very interesting stuff.

jeff <><

It is like a 223 and a 45 auto. Each one will kill a person very easliy. It all depends on how fare away one wants to do this killing. A 45 auto will not kill past a hundred yards, but for the 223 it will do it father out. Also i was wondering if one could make a hollow point gland?

Ah yes, ballistics. ;D
Gun, a .45 will most certainly kill someone at 100 yrds. It retains it's energy much better than a .223.

When talking about lethality there are a couple of points to consider. To kill a person you have to effectivly disrupt vital organs, destroy major blood vessels, or destroy the central nervous system. To do this you can simply burst or crush tissue through energy transfer, or you can cut a long hole though it all. Statistically, the lowly .22 is responsible for  most deaths in which a firearm is used. Due to it's light weight, it tends to bounce around inside someone, and because of it's small diameter, and surface area, it isn't slowed down much by tissue creating a very long wound channel. The .22 doesn't blow up or crush tissue, it just pokes a very long hole that results in tremendous bleeding. The .45 is so large and heavy (as high as 250 gr) it crushes everything on the way through, leaving a permanent wound cavity the size of a cantaloup. The .223 (usually about 55 gr) is a really small bullet, but it's traveling really fast. Water doesn't compress. The .223 is traveling so fast it displaces water in tissue at a remarkable rate causing sort of an explosion, Hydrostatic Shock, likewise creating a permanent wound channel.  But even the .223 isn't considered a substantial enough round to be legal for Deer hunting in many states.  Now, a .308 is nearly as fast as the .223 and just about as heavy (180gr) as the .45. Lemme tell you, that is a nice round, and it's about average on the list of calibers used for big game hunting.  Anyways, I'm getting off subject...


As far as sling ammo goes:

Hollow points were developed to prevent bullets traveling at high speed from going right through the target without doing much damage. If I shoot a milk jug full of water with a FMJ it will poke a clean little hole in both sides of the jug and burry it's self a foot or two in the ground behind it. If I hit a milk jug with with a Hollow point it will vaporize the milk jug and bury it's self a couple of inches into the ground. That's because the Hollow point capitalizes on the target's resistance to penetration. The cavity in the front of the bullet catches the target and forces the bullet to expand 1 1/2 -2 times it's original diameter; the larger surface area is much more efficient in transfering energy to the target.  For the velocities we are dealing with, making a hollow point Glandes will just mess up it's areodynamics. What we have is a big, heavy, projectile, 2 oz = 640 gr (i think). It isn't going as fast as a bullet so I dont think penetration is the key, though they certainly can penetrate flesh, plywood, skulls, etc... In my humble opinion, I'd say that a slung projectile's strength is it's tremendous momentum created by it's mass. When it hits, it crushes the tissue, breaks bones, and bursts muscle and vascular tissue. It's like getting hit with with meat tenderizer. The denser the material used for the glandes the less it will be acted upon by wind resistance, keeping it's momentum intact for the target.

A .308 shot from my rifle has about 2800 ft-lbs of energy at the muzzle and about 2300 ft-lbs of energy at 100 yrds. My recuve sends an arrow down range with about 50 ft-lbs of energy at 25 yrds. Both of them will kill a deer plenty good. My bow could probably even kill an elephant with a properly placed arrow. That's the difference between cutting a 1 1/8in wide incision through the vitals of a deer with a broad head, or turning the vitals into a red froth with a .308. With a Sling, I'd say it's method of lethality is more closely related to a hammer than either a bow or bullet.

Nw....you know yer stuff.  Couldn't have put it better myself!