General >> General Slinging Discussion >> Got in some practice today

Message started by JeffH on Oct 24th, 2003 at 8:46pm

Title: Got in some practice today
Post by JeffH on Oct 24th, 2003 at 8:46pm
Hello Friends,

I went out today to shoot bows with my daughter.  Just made her a longbow and accessories last week.  We had a great time.

I took along my slings just in case there were some rocks in need of throwing.  Well, what do you know, there were.  I threw several dozen, mostly for distance, very few for accuracy (which was good because I don't have any.)

I used two different slings, one with four #24 strands in the cord and one with four #72 strands.  You can see these in the gallery.  The #72 is the newest with black pouch and white cord.  I threw stones of varying size from about 1.5 oz to maybe 5 oz.  They were various shapes as well.

I threw a lot of them at some woods about 225 ft away.  Straight line throws mostly.  When the stones contacted the trees it was a sound to behold!  Much power in those stones, many whirring loudly as they went (the more gland shaped ones that is).  I also threw some in the 30 to 45 deg. range for distance.   With different size stones, I easily cleared the tops of some 70 ft pines at about 225 ft.  How far did they go?  I don't have any idea, but I don't think over 300 ft is out of the question for some of them.  I could throw to around 160 ft with almost no inclination to the release.

Now, here is the cool part.  These were all single windups.  No multiple rotations at all.  I did try some double and triples, but could not control the release.  No feel for the stone's position, it just wanted to keep going 'round.

Also of note was the tremendous power of the stones.  As they went through the woods, they often clipped off small limbs.  They fell as if clipped by bullets from a rifle, no vibration or moving in the direction of the impact, just straight down.  (I have witnessed this many times with bullets hitting limbs.)   When they hit the trees, it was solid and loud.  I have no doubt that a 2 or 3 oz stone could very likely kill a person at 50 to 100 yards if hit in the head.  A 5 oz'er would be devastating indeed.  

The velocity was several hundred feet per second at release.  My arrows go around 180 fps from my recurve.  The stones were much faster when thrown well, possibly as much as 300.  I gave a very strong flick at the end of the throw.  Of course, with a very poor aerodynamic coefficient, they slow down quickly, but I still have no problem believing in Yurek's well practiced 400 ft + thows.

BTW, these slings are my standard 34" from loop to center of pouch.  I wear the loop over my ring fiinger and lay the cord through my hand.  So, about a 32" sling +/-.  I found the smaller cord more friendly in some respects.  The larger cord seemed to make the joints of my hand and fingers hurt worse.  Don't know why.  It also has much more inertia to overcome when the stone is opening the pouch.  Needs larger stones.  They both wrapped completely around me after each throw.  Had to undwind myself.  This was worst when throwing straight since my release is more horizontal than I realized before.

Jeff <>< who had great fun today.

Title: Re: Got in some practice today
Post by Chris on Oct 25th, 2003 at 1:49am
I don't think 150 mph (~300 f/s) is impossible, in fact i think it's quite likely, especially with longer slings.  If you think people can throw things with their arms at 100 mph, a 3 foot sling could easily bypass 150 mph.  

I've heard that rewarding sound too and often see limbs falling down after impact from the stone.  However, I don't think I could kill a man, even with a head shot.  It takes more power than you think (unless you get them in a very lucky spot).  But I've never killed a man... so I'm not positive.  :P


Title: Re: Got in some practice today
Post by JeffH on Oct 25th, 2003 at 2:00am
On the other hand, we humans tend to be rather frail.  Goliath, a rather stout giant, fell to a stone.

If a 5 oz stone impacted at 150 fps it would have an impact energy of 109 ft/lbs.  While low, I believe this would be enough to kill if properly placed.

Now, to be a bit less morbid, this could easily take small game like rabbits.  You might even stun a javelina long enough to stab it with a spear.  Meat on the table. MMMMMM!!!

Jeff ><>

Title: Re: Got in some practice today
Post by David_T on Oct 25th, 2003 at 8:31am
Yeah!! I killed a bear the other day with a head shot ;D
Actually it was only a dog---would you believe a cat? Ok it was just George. But it knocked the bucket right off his steel neck!
I have no doubt at all that it is a     ly weapon in the right hands or lucky hands. If the Spainiards wrote of the Peruvians         a horse-- a man's head is not that hard. Well, I guess some of us are hard headed but you get the point.

Title: Re: Got in some practice today
Post by David_T on Oct 25th, 2003 at 8:33am
My computer censors d e aa d l y  and k i l l e d

Title: Re: Got in some practice today
Post by Chris on Oct 25th, 2003 at 9:43am
It takes 72 ft/lbs to fracture a human skull.  I'll try to post a link to an army corp explosives powerpoint presentation which has this data for the human body.  

How did you get your foot/lb calculation?  A book I have copies off says the sling achieves about 30 ft/lbs, but I think that is low.  


Title: Re: Got in some practice today
Post by JeffH on Oct 25th, 2003 at 10:48am
Whatever resource says the sling generates 30 ft/lbs should be read with a jaundiced eye.  There is a lot to this.

See my new post on this subject  

Jeff <><

Title: Re: Got in some practice today
Post by Yurek on Oct 25th, 2003 at 10:09pm
You guys have inspired me to play with nubers. But I had a little problem with your energy unit [ft/lbs] we mainly use SI metric system and a joule [J = Kg*m*m/(s*s)] is a energy unit.

Physical formula for kinetic energy is:

KE = m * v * v / 2     [J] = [kg*m^2/s^2]

m - mass               [kg]
v - velocity           [m/s]

On the website: (maybe this site would be interesting for Jeff as archer) I founded the following formula:

KE = (weight / 450240) x (velocity x velocity)        [ft/lbs]

weight      [grains]
velocity    [ft/sec]

I'm not able to estimate the initial velocity of my shots, but it isn' difficult for a medium velocity along the trajectory. I practice a lot for range and recently quite often reach the distances over 300 m. The trajectories of my shots are rather flat (20 - 30 deg maybe), so I estimate that for the range 300 m the way of the stone is about 330 m (trajectory curve lenght). The stone flies about six seconds and its medium mass is 0,12 kg (120 g).

So the medium velocity between the release point and the drop point is:

MV = 330/6 = 55 m/s = 180 ft/s = 198 km/h = 123 miles/h

I don't know the release velocity and the final one and don't know where the temporary velocity is equal to the medium one on the trajectory. So I accept a large simplification that in a half of way the stone velocity is about 180 ft/s.

So the impact energy after about 150 m flight is:

0,12 kg = 1851.88 grains

EK = (1852 / 450240) * (180 * 180) = 133 ft/lbs = 182 joules

Of course just after release the stone velocity and energy must be a much greater. I saw the marks on the wall, on tree trunks and others. I'm sure the sling can kill not only men but a big animal too, by body penetration. The stones which hit something stiff are shivering often, sometimes they crak durring the release even.

So I pray that to hit somebody never. I like a power of sling but I don't want use that as weapon. I'm a good boy and I'm afraid that bad boys will play with sling :D

I have no doubt at all that it is a     ly weapon in the right hands or lucky hands

David, I think it should be rather like this:

"I have no doubt at all that it is a     ly weapon in the bad hands or unlucky hands" ;)


Title: Re: Got in some practice today
Post by JeffH on Oct 25th, 2003 at 11:10pm
Great stuff Yurek!

Did you say 300 meters?  That's over 900 feet!!!!!!!!!!


Jeff <><

Title: Re: Got in some practice today
Post by Whipartist on Oct 26th, 2003 at 2:01am
GREAT STUFF!  I'm enjoying this to no end!  Great posts!

Chris, I wonder what portion of the human skull the power point is speaking of?  There are significantly different thicknesses in various portions.  I think behind the ear is one of the thickest but the front of the skull is a lot thinner, there being sinus cavities all up the front.  

As for killing power.  I think there are several factors though.  A knock out (concussion) can kill.  It involves the brain hitting the side of the skull and hemoraging.

Primative conditions render many flesh wounds potentially deadly.  Infection can kill.  If I'm a primative slinger and transfer primative germs from my primative unwashed hands to my primative projectiles.  And they penetrate or cut into my primative thinking opponent.  Then he may take his primative unwashed hands and get a primative and deadly case of gangrene.  I've heard this was a big cause of death in midevil battles.  Slight wounds would get infected and the warriors died.  

Another factor is bruising.  If a major muscle, like the leg muscle, is struck hard enough, it can be rendered temporarily inoperable.  Slam your knuckles into your bicep and you'll find it out.  If a sling stone came down on a warriors foot, shin, thigh..., he's toast.  He won't be able to fight well enough to live after that.  

I suspect that sling stones could break the ribs pretty easily.  I once busted a hole right through a pretty sturdy fence board, with a lead fishing weight slung out of my sling.  I was impressed!  And of course lead glands were known to penetrate bodies in battle.

In my experience with the sling, it is a very powerful weapon.  I would be terrified of a good slinger using me as a target.  That 30 foot pounds figure is very low.  There are high powered pellet guns that can equal or beat that.  And they are firing tiny pieces of lead.  I use rocks or glands weighing between 4 and 5 oz.  Jeff's story brought back fond memories for when I used to cut big limbs off the walnut trees in a field where I used to sling.  I could cut limbs right off that were about 3/4" diamater and sometimes 4' long or so.  I think a rib wouldn't be harder to break than a fresh tree limb of the same size.  Bones are strong but a quick shock breaks them.  Just like steel is strong but you can snap a knife blade.  Anyway I'm just ranting!!

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