I know the subject have been discussed several times, but today I did a casual 'experiment'. Going back from our 'weekend snow-ball slinging' walk with my dog, I found an wrinkled stone. Of course, I couldn't resist myself and popped that one into a pinery. The stone hit and cracked a quite solid limb off. The pine with the limb was ca 30 m away. It would be nothing new and and strange, but the stone, after a moment, landed on the ground very close to the broken limb. Hence I got the both things back and took a few pictures of them. So we have got a small photograhic evidence of sling stone impact. I must say, the limb was so hard and sound, that I wasn't able to break them by the hands, using all my power, and sometimes sling stones can break much thicker limbs.

http://www.kajakowe.com.pl/sling/IMG_8616-copy.jpg

http://www.kajakowe.com.pl/sling/Untitled-1.jpg

On the socond picture you can see some crushed layers that took a first part of energy. Imagine, what would be if it was a bone...

Jurek

That's power! 8)

You are the man, Jurek!

Yurek
Great power..!
Still snow on the ground..? It was 79degrees here in Tennessee today..!
Johnny

That looks like a real good solid hit! :)

40F here :-/ rainy too :)

nice hit! ive broken branches off of trees too. I always thought that they where rotten, maybe i should look at them when they fall :)

I would say, that given the fact that wood forms in a very similar maner to bone, we can infer what would happen to a very thick bone if it were hit by a slingstone, expecially a chunk of ferric rock thrown by our own Jurek!  That's really impressive, actually. The best I've ever done was a stone thrown at a large tree which I managed to miss, but took off a branch about as thick as my thumb that was toward the outside of a far branch. Had the same breakage pattern and everything, but nowhere near as thick a branch, to be sure!

i often clip off smaller branches with my sling stones, and once or twice i have dropped some larger ones.  

I've broken branches too.
I particularly like it when you sling low, and many of the ground plants, fall in a line as if suddenly snipped with an invisable blade.

Although, many bones of the body are padded with fat or muscle there are a great deal exposed to external blunt trauma. Take the radius and ulna in the arm, or other long bones like the ribs or tibia, these are very vulnerable. The flat bones  in the skull seem particularly open to this assult.

If I remember correctly some martial schools in acient japan trained their swordsman in slicing/chopping limbs, by wrapping bamboo with straw mats. This would effectively simulate flesh on bone, and offer a more realistic resistance to the blade. I don't know much regarding this testing system, but you can find more if you look up "Tameshigiri".

I wonder if we couldn't set up a similar system for slinging, to measure a stones impact. Considering how much force might be obsorbed by skeletal muscle we might find some compeling results.

-Unsapien

force=mass*acceleration, so if we take a 4 oz lead bullet, and send it forward at what? 120 mph? we could measure resultant force and compare that with what force it takes to break bone, we could find out what a sling bullet travelling at 182 kph would do to a human body. 20, 979 lbs/force is what I got, which is almost double what it takes to break a human parietal bone. or since the measurements were in metric, do I have to divide the figure by 2.2? regardless, a small glande travelling at even a moderate 182 kph has enough energy to crush a skull.

 Impact is measured in foot pounds, from what I understand. I got this from Robert Dohenwald, in his article, The Sling, the forgotten firepower in antiquity.
 As  he had it figured out, a 1 1/2 oz. stone would hit with a force of 52 ftlbs. This is roughly equal to being shot with a 22.
 As the weight goes up,so does the effect, exponentially.
 It only takes 18 ftlbs of force to penetrate the bones of the face    

Compelling,
Does anyone have access to ballistic jelly?
-Unsapien

  Who ya gonna call?
   MYTHBUSTERS!   ;D

Ballistics gel is more or less knox gelatin, right? The clear, unflavoured stuff you can buy in the market and mix in a bathtub? Get enough of it, insert some bones made of clay/sticks, set up your own private "Buster" and start hurling!

wrote on Mar 13^th, 2006 at 12:03pm:

Impact is measured in foot pounds, from what I understand.

Force = mass*acceleration
Impulse = Force*time (how long the impact lasts, that is)

the SI (standard) unit for Impulse is a "Newton second" (N*s)

Note: a Newton is equal to a "kilogram meter per second squared" (kg*m/s^2) because mass is measured in kilograms and acceleration in meters per second squared (m/s^2)

as a side note: one newton is 9.8 meters per second squared.  this is the same as 32 ft per second squared.  at leat here on earth.  obviously this is varied slightly due to differences in altitude, so this is really just an average of sea level, but it works for a general rule.

for someone who got all this in highschool i should understand what the hell you fellas are going on about :-/ all i get is Yurek broke that branch wich i think means it can break bone...not to mention Yurek is one hell of a good shot :o

Maybe this thread ought to be Titled "Why MammotHunter Failed Physics but Enjoyed Every Moment of It."Impact ballistics always enticed me, but as you can see, I was never any good at it. so, I've learned something here. I still can't tell you what kind of force the rock imparted to the branch, but what I can tell you is, nobody ought to be standing roughly 1500 metres around Jurek in any direction when he's having a bad day. ;)

In terms of causing damage, flat rocks are really enjoyable things to sling. I've slung them before using the Greek style, and they cause some pretty insane damage. They don't bluntly smash anything like Yurek's rock did (insanely powerful hit, BTW) but they can cut off branches thicker than anything I can break with a regular stone, and they even manage to cause gashes into the trunks of trees. I once saw a gash from a flat stone on this one tree (think it was oak) that looked as if it was done by slashing the tree with a machete. Plus, flat stones make an awesome wizzing sound when you release them.  ;D

I love that sound!:)
Even though it means your losing power.

Making ballistics gelly is a little more involved than I thought, but if anyone is willing to try he's a link on how.
http://www.recguns.com/Sources/XD3.html

Speaking of impact,
I was slinging yesturday at my range with a friend of mine whom I believe is starting to really enjoy slinging. We started  slinging rocks at the targets, but had to stop because the ammo was disappearing. The rocks were drilling themsleves several inches into the targets. These targets were highly compressed rice straw (3 bales compressed into one smaller one), and were wrapped in a heavy plastic, with of course cardboard as targets.
I was amazed, these targets are fairly new. I helped put them in myself. My friend and I sling a few more stones to make sure we didn't just hit a soft spot.

Larger stones, 3/4 of a tennis ball, could not penatrate,
but roughly golf ball sized stones could,
and small pebbles hardly damaged the cardboard.

This expirence has given me more appreciation for a slings power. After slinging for awhile you forget how fast the stones are going.

-Unsapien

wrote on Mar 14^th, 2006 at 6:08pm:

as a side note: one newton is 9.8 meters per second squared.  this is the same as 32 ft per second squared.  at leat here on earth.  obviously this is varied slightly due to differences in altitude, so this is really just an average of sea level, but it works for a general rule.

No. One Newton is equal to one kilogram meter per second squared. Acceleration due to Earth's gravity is equal to 9.80 meters per second squared. So by multiplying 9.80 m/s^2 by the mass of an object in kilograms you can find the force gravity exherts on that object. However, I think we were more interested in the force the object exherted on the target it hit. For this we'd have to solve a collision problem. ::)

wrote on Mar 14^th, 2006 at 6:29pm:

what I can tell you is, nobody ought to be standing roughly 1500 metres around Jurek in any direction when he's having a bad day. ;)

i can see it happen now people running in fear when Yurek leaves the house in a temper clutching his sling and a sack of stones Lol ;D

maybe mythbusters could do a epersode regarding david and golith instead of trying to use a sling themselves they could fly jurek to america or get an apache to demonstrate

anyone thought of contacting them

wrote on Mar 15^th, 2006 at 1:25pm:

instead of trying to use a sling themselves they could fly jurek to america or get an apache to demonstrate

It doesn't seem like something they'd do. They like to do everything themselves.

Yurek,

Great Hit and recovery of the rock "whodunnit."

Close scrutiny of impacts has been one of my favorite parts of slinging.  That branch really shows both the force and "lumpiness" of the rock.  A femur would have snapped like a toothpick.

Slinging into the forest is particularly fun when you get a solid hit with a resounding "Crack."  With addition of Figure 8 technique I got two consecutive hits within 5 cm of a knot at 15m range.  I can now pick which tree is the target at 100m range and helped a tree across the river shed it's leaves last autumn with a few central hits that shook up the whole project.

Your trophy branch looks about right for a staff sling...

By the stone harvested
More stones to hurl.

AjlouniBoy

I'm sure, for some of you  it wouldn't be a big problem to crack that branch or even a thicker one. Besides, there is a significant influence of the mass of stone. For instance, if we are slinging two stones, seratim, a bigger and smaller one, providing to them an identical kinetic energy (in this case the smaller one must be faster: v = quadratic_root(M/m) * V), the bigger stone (M) is able to break thicker and stronger branches. So, looks like the momentum (m * v) is more sinficant factor if you want to break, overturn or crush a target (a penetration is an other quetion).

Saying simply, if a slinger sling a one pound stone with his full strenght (rather slowly due to the big mass), most probably the stone will make a bigger disaster among brunches, than a 2 oz stone slung extremally fast.




Quote:

By the stone harvested More stones to hurl.

Thank you AjlouniBoy! I also like to watch results of impacts :)

I've found that... When you fling a small stone, no matter how fast, it continues to get stopped by branches... i grabbed a few large rocks and flung em into a bunch of branches and was able to make a path that i could basically walk into

(maybe im exadgerating... it took quite a few stones but all of them were big and devastating :P)

;D SlingWolf ;D

Birth of a new form of brush clearing?

not nearly as much fun as slash and burn. I don't have many trees in my yard so wouldn't think of using them as target practice.

There is an old medical treatise from the Middle Ages by a doctor named Celsus.
 In it, he states that sometimes the lead glandes would be stuck into the bone so deep, it was impossible to pull it out.
  What he recommended doing is make the wound wider, and cut it out of the bone by cutting a v notch.

That sounds a bit painful.... but... what must be done must be done...  :o

;D SlingWolf ;D

I heard that roman surgeons actually developed a  specialised instrument for pulling embedded glandes out of patients.

Just to make you feel worse probably...
"Oh no... they're bringing out 'the tool'. Hey.... if you die.... Can i have your stuff?"

;D SlingWolf ;D

i just took advantage of the nice weather to get out and lob some golfballs actually hit a some trees too ;D (jeej i feel good) not to the effect this thread talks about But it is a start  ;D

i just wonder how long is your sling,  and wich style do you use to get such power.

good hit yurek. I have had many broken cedar fence bords to atest to the power of the sling. thanks for the pictures yurek

I got back into slinging only a year and a halfish ago and am using a normal David style one, I still haven't mastered it but that smashes rotten stumps to peices at 30ish meter  ranges and cuts branches when I miss but not useully that big unless they are dry.( so good shot! ).  When I was in my early teens I used a an uneven lenth cord sling mounted on a short ( about forearm and a half lenth ) stick.  the retention cord was attached to the top and the releace cord ran down through a hook ( the sort used for net curtains ) next to the top in the side.  So about an inch apart, too much less than this and I had a problem with twisting.  I'd hold the stick at the bottom and the end of the releace cord with my thumb against the stick...and that did have power.  With it I could stick a stone an inch or two into a healthy sycamore ( I stopped doing that because they bled for days after and I felt guilty. ).  At short range, really short about ten or fifteen feet maximum,  if one shoots at a milk bottle with a handful of shingle, about pea sized, one gets lots of holes through the bottle but it doesn't smash.  So I guess that must be pretty good for velocity, my friends air gun at the same range smashed them.   It was one of those towns and people used to shoot at us with airguns ( .177 webblys ( sounds like that anyway ) with .22 springs in them., I still have a scar on my cheek just under my eye from then.  Well this annoyed me and rather rather spoiled playing in the feild so I slung back one time ( not to hit, even angry I wasn't insane ), one of them was by a tree which was about twoish cricket pitch lenths away and about half a cricket pitch up.  The rock buzzed into the tree not far from his head and stuck in quite deep, that sounds better than it really was as the tree was a soft bark poplar   Even so he, took one look at it and decided to amble away his mates left too,  occasionally taking potshots as they went but even when they got to the top of the hill and were shooting up at 45 degrees we were well out of their range but they still had my rocks falling from the sky around them.  After that we were ok playing in the feild.  I don't really know what range that was as for us a cricket pitch was 22 uncomfortable strides and a cricket bat and a handle either end for the creace, probably the air guns wern't all that good either but still it was easily the best ego trip of being fourteen that one.  

Stringman,

What is the "normal David style"?  Do you mean the "helicopter" style where you wind up several turns over your head and then let fly?  Or the style shown in Bernini's statue (David is halfway through the windup, just about to let go of the rock)?

And welcome back to slinging!

Thanks for the welcome Dale.  By David style I mean the usual type of sling, two lenths of cord with a pocket, the sort most people use.  The thing I made wasn't quite a staff sling as the cords were as long from the pocket to the end of the stick as the stick was long.  The thing was  I ddn't know any slingers or have any referance on slings bar a tiny entry in an encyclopedia which only used the term staff sling and mentioned that ancient celts used to get a longer range with them than with a shepards sling so I just made it up. I got it wrong as now that I've read around I know that a staff sling is more on the principle of flicking peas with a spoon, but I got it wrong in a pretty good way.  So I don't know a proper term, if there is one, but as it is effectivly a sheperds sling on the end of a stick with a longer release cord to reach down the stich to the hand, I called it a mounted sling.   Whatever it is it is pretty powerful.  As to technique it is little differant.  What I favoured was to bring it round once as one does with a shepards sling for low side arm but at the end one also whips the wrist round  for a bit extra power, the trick is to start the movement in the body but have the shoulder then the elbow and near the end the wrist all whip together at releace.  Easier than it sounds.  So far I haven't made a mounted sling again but think I must soon ( might even try putting it on a quarter staff and see if the extra leverage makes up for loseing the wrist action ), trouble is one can't just roll one up and keep it in the pocket.  So in a way I'm actully new to slinging with a "proper sling" and so far am still playing with style, I tend not to use wind ups except for larger rocks as it seems to make me less accurate for very little gain in power but that could simply be because I haven't practiced enough yet.  I favour bringing the rock from above my shoulder on the left, diagonally behind me  me and releasing low on the right, but that may be because it is nearest to my old mounted sling method.  Tried apache and find it is vertically pretty accurate but haven't managed much power with it yet.  Side arm is ok but if I miss, or the stone catches in the pocket it is to the side and that is generally a more dangerous miss as I do most of my slinging in woods and in company.

Stringman,

You are on the right track.  Much windup leads to much error.  Most of the slingers here favor a small amount of windup; the sling swings through only a couple of circles, or even less.  My best style is the Apache style, which starts with the sling hanging at my side and a bit behind me, and the sling is swung through only about 180 degrees before I release the rock.

I mis-read what you wrote; I thought you were talking about the style of slingING, but you were talking about the style of SLING.  Actually, your miniature staff sling sounds quite powerful.  I would like to see a picture of it, so I could make a replica and try it out.

Imagine if that were bone...  Ouch

Dale

Wish I could oblige but it was quite some time ago, three decades, I moved away from the place at 15 and one of the farewell swaps was the sling, I got a catapult.  It was the move that put the pause in my slinging probably, just life stuff.  To be honest it wasn't a masterpiece of craftsman ship but for the record I'll describe it anyway.  The stick was about the diameter of the second joint of my thumb after I'd stripped the bark off, I think it was old wood elderberry.  Dead and well seasoned, beautifully straight hardly any taper at all.  Probably any wood that doesn't flex would do.  I whipped one end of it with string for a good grip in exactly the same way one would whip a rope end to stop fraying.  Not counting the string grip the length was from my wrist to halfway between my shoulder and my elbow   I then scraped the stick smooth with a piece of copper I'd sharpened ( my parents wouldn't let me have a knife then )and crushed the surface of it with the side of a screwdriver to make it smoother finally I buffed it with a handkerchief and ,this is maybe where you give up on the EXACT replica idea, some ear wax.  I had got hold of a brass hook from somewhere, I think it was designed to screw to the bottom of shelves for holding cups, it had a long deep  tapered thread.  I screwed this down the center, where in most other woods the knot would be.  I also screwed a small eye into the side at the top, later I changed this to a small hook for faster loading.  Both the latter fittings were the sort used to hold the wire for net curtains.  The fabric bit was really simple, the pocket was a strong canvas on one side and leather cloth ( plastic side out ) one the other, I put seams all the way round both materials and then put them, seams together and stitched them together. I'd left long square ended tails either side of the pocket and simply stitched these back on themselves to become loops.  The cords were just cotton string which I fed through the loops and tied, I thickened the retention cord with chain hitching for it's entire length.  I also thickened the release cord the same way but only to half an inch  short of the top of the stick, about half it's length, after which it was single.  I've missed out several of the slings evolutions as it took a while to get it just right but that part is important as the release cord has to run smoothly through the loop or hook. In fact a knot on the release cord is a bad idea as if it catches on the loop the stone can catch on the string and it's random shot time, I learned that the hard way.  I tried whipping the end of the cord with cotton which helped but as it was only string I often just let it fray, it was good for a few hundred shots anyway.  Bear in mind that I was a ten or eleven year old with little knowledge and feeble skills when I made this.  

I don't think it was a miniature staff sling though, it's not like any staff sling I've read about anyway; the cords are of uneven length, the release cord runs right down the shaft, not to a toggle in a notch at the top, and is released by hand at the bottom. Doesn't work quite the same way.  Until I know better I'll stick to the term mounted sling.  If bow type weapons can be subdivided into bows, crossbows, arabesques etc why shouldn't we have slings, mounted slings, staff slings and trebouches ( does that put us one up?)    

Much as I'd like to claim the credit for inventing some new sort of sling it probably isn't. Aside from being such a simple idea that it probably gets “invented” a dozen times a year by someone, I've read somewhere that the ancient Greeks had many lewd pantomimes in which staffs carved into the shape of phallus's figured.  ALL these plays have been lost, unlike the tragedies, and apart from a few critical references and many of the staffs nothing remains of them. I have also read that slings with uneven length cords have also been found and that the manner of their use is unknown.  Well could it be that the archaeologists are finding two parts of the same thing?  The staffs would be just the right shape for a slipknot with a fixed loop (perhaps around a ring with a groove around the outer side)in the loop.  But who am I to suggest that given a slightly phallus shaped bit of kit the lower ranks in the Greek army would be crude enough to make them even ruder.  I apologize to any modern armed forces types who are shocked by such a suggestion.

Also sorry for the length of this post but hope it makes up for the lack of image.  Just writing this makes me want to have one again so I'll pack my wire saw just in case I happen on the right bit of wood when I'm out.  To return the subject to impact.  This is unfair as I used a mounted sling a lot over four or five years and a standard sling only a year and a half about an afternoon a week but inches equal, folded length of sling compared to stick plus retention cord lined up in a mounted sling. I got more power out of the mounted.

Hi, this is a question for Yurek. (or Jurek, not sure which you prefer...)

I really like your pouch idea, but I seem to have some difficulties.

First, the cup made by the folding held the stone too well, making the release rather painful. (besides losing power)

So, could that be fixed by making it more narrow? my pouch was almost twice your pictured width as well as length. Also, I didn't use leather, so the cup was rather deep. Does leather tend to be shallower?

Next, Do you use knots to attach the pouch to the cords? Or is it just tight binding?

And lastly, I didn't make the slit in the middle. Does that make a difference?

Thanks,

8)

Bring your sling to an archery range and surprise the archers, if allowed. ::)

Southpaw,

Jurek has given us a lot of details about how he makes his slings.  If he doesn't reply, you can still read what he said in the past in this way:

• Click on the "Members" link at the top of the page.
  
• At the top of each page of the members list, there is a link labeled "View by Letter"; click that link.
  
• Click on the "Y" link.
  
• Click on "Yurek".  Yeah, it's different from his name, but he chose that user name so that we Americans would SAY his name correctly.
  
• At the bottom of his profile, there is a line that reads "Show the last <list> posts of this person."  Select "All" and click "GO!"
  
• The list is presented with the newest items first.  Happy reading!
  

Sweet, thanks Dale.

This will probably stop my endless flow of questions. ;)

8)