# Blunt trauma?



## Jacktrevally (Feb 14, 2011)

What is blunt trauma? Explain please?


----------



## treefork (Feb 1, 2010)

*Definition* of *BLUNT TRAUMA*. : a usually serious *injury* caused by a*blunt* object or collision with a *blunt* surface (as in a vehicle accident or fall from a building) <the patient died of *blunt trauma* to the head>-called also *blunt* force *trauma*.
In the case of slingshots your killing will the force/ impact more than penetration with the projectile with bleeding.


----------



## Jacktrevally (Feb 14, 2011)

Impact- that is the rate of change of momentum?

What I don't understand is is why do we slingsooters talk about energy!!!???


----------



## THWACK! (Nov 25, 2010)

When someone smacks your head with a baseball bat, that's blunt trauma.

Regards,

Mike


----------



## Nicholson (Sep 25, 2012)

Jack trevalty, I think the energy at least gives us numbers and it's something that can be calculated. You can get clean kills with a 5/8 marble at 4 foot pounds of energy with good head shots. Blunt force trauma is very deadly for game that's why I prefer at least .45 cal lead for hunting


----------



## Nicholson (Sep 25, 2012)

Jack trevalty, I think the energy at least gives us numbers and it's something that can be calculated. You can get clean kills with a 5/8 marble at 4 foot pounds of energy with good head shots. Blunt force trauma is very deadly for game that's why I prefer at least .45 cal lead for hunting


----------



## Blade (Jun 5, 2014)

Foot pounds of energy is good for figuring out how much power you are achieving because its a standardized scale. 8 foot pounds is 8 foot pounds. Speed is relative to what ammo you are using where as energy is not. Now ammo can deliver a different energy depending on expansion and penetration but FPE is a good baseline for hunting effectiveness.


----------



## Jacktrevally (Feb 14, 2011)

So there's a little question for you.

what will you choose?

A 1.5grams lead ball moving at 400fps or a 5g marble moving at 160fps?

I bet you went to feed that in a calculator did you!? Lol


----------



## Nicholson (Sep 25, 2012)

1.5 grams that's about the size of a bb? My nephews play air soft and their guns shoot 400 fps nobody complains about getting shot. A marble can be used to hunt but id want about 200 fps with a headshot. With those 2 options your better off hunting a pop can


----------



## Jacktrevally (Feb 14, 2011)

That is a 1\4 inch lead ball! I'm pretty sure that will bloody hurt if that hit someone at 400fps.


----------



## Blade (Jun 5, 2014)

Nicholson said:


> 1.5 grams that's about the size of a bb? My nephews play air soft and their guns shoot 400 fps nobody complains about getting shot. A marble can be used to hunt but id want about 200 fps with a headshot. With those 2 options your better off hunting a pop can


Your probably thinking of .15 grams. A normal airsoft bb is .12 grams


----------



## Nicholson (Sep 25, 2012)

I just got home and weighd a bb. Yup only .4 grams. The closes thing I could find to 1.5 grams is a piece of sweet tart candy at 1.1 grams. My hands may be a bit calloused but I couldnt even feel that in my hand i couldnt imagine hunting with it. you probably be able to at least stun a spruce chicken long enough with the marble on a head shot at 160 fps and collect and I'm assuming it's a hypothetical question. 7.5 gram steel at 160 fps is enough to hunt with though


----------



## DogBox (Aug 11, 2014)

Yeah, most people set the Tonearm of their record player at 1.5 g. The heavier weight, although travelling slower 160 fps is the more forceful.

Nicholson said:

I just got home and weighd a bb. Yup only .4 grams. The closes thing I could find to 1.5 grams is a piece of sweet tart candy at 1.1 grams. My hands may be a bit calloused but I couldnt even feel that in my hand i couldnt imagine hunting with it. you probably be able to at least stun a spruce chicken long enough with the marble on a head shot at 160 fps and collect and I'm assuming it's a hypothetical question. 7.5 gram steel at 160 fps is enough to hunt with though 

DogBox added:

With 1500 posts I woulda thought Jacktrevally would have come across that by now...? or is he teasing us!


----------



## Jacktrevally (Feb 14, 2011)

I have come across a few discussion on these over the years.

Actually a 1.5gram ammo moving at 400fps has about twice the energy of a 5grams ammo moving at 160fps.

So what to believe now???


----------



## Blade (Jun 5, 2014)

DogBox said:


> Yeah, most people set the Tonearm of their record player at 1.5 g. The heavier weight, although travelling slower 160 fps is the more forceful.


The smaller lead will have around 8 fpe compared to the 5 gram ammo's 4 fpe.


----------



## Nicholson (Sep 25, 2012)

that's pretty minimal but possible. better get the soup can out and test them  should get the marble up to 200fps though which is easy to do


----------



## wll (Oct 4, 2014)

Unlike foot lbs of energy, M x V squared/450250 Momentum is a function of pure mass x velocity.

A 22lr has about 128fpe but 48,000 units of momentum

A 120gr lead ball at 200fps has only 10.6fpe but has 24,000 units of momentum ... half of what a 22lr does

The blunt trauma of a slingshot is pretty impressive

If you use the Taylor Knock Out formula the sling shot is even more impressive, with a slingshot it is about the smash

22lr ......... 40gr x 1200v x .224dia = 10752/7000 = 1.538 Taylor

Sling Shot ......... 129gr x 200v x .385dia = 9240/7000 = 1.32 Taylor

Taylor factor was used for an non scientific unit to measure the effect of bullets on game, showing that big heavy projectiles are very effective on game animals. Taylor devised this formula after hunting and seeing thousands of animals being shot by a variety of calibers and seeing the effects of heavy slower moving projectiles on game. It pretty much has stood the test of time in real life situations.

wll


----------



## DogBox (Aug 11, 2014)

How do you get 1.5g to move at 400fps...? by something else other than a 'slingshot...!

DB


----------



## Jacktrevally (Feb 14, 2011)

I'd an overview of the Taylor knock out and the Thornily formula which has an index chart.

Quite interesting!

The product of momentum and energy gives another interesting value called the kinetic pulse.


----------



## Nicholson (Sep 25, 2012)

slingshot hunting is different from rifle hunting. In Rifle hunting the bullet must penetrate and it counts on blood loss to kill. You can factor in kinetic pulse, hydrostatic shock and whatever else rifle hunting science involves. Slingshots use blunt force trauma to kill for the most part and a heavier bullet is more effective givin enough velocity in this regard. As for kinetic pulse, the heavier bullet with a larger mass has more kinetic pulse or punch. The lighter bullet of less mass will disrupt less. Both can release the same kinetic energy but the heavier bullet will move a greater target mass at a lesser velocity than a lighter bullet at a greater velocity. Now I havnt studied kinetic pulse enough but with slingshots the ammo shoots at a much slower velocity than rifles so kinetic pulse isn't much of a factor, or is it? When in doubt do the soup can test(the slingshot ballistic test)


----------



## Jacktrevally (Feb 14, 2011)

This is where the kinetic pulse punch in. It shows that a slow vel projectile with great mass may have a relatively bigger momentum but lower energy whereas a fast moving light ammo may have less momentum but higher energy. The productb of energy and momentum gives an indication of the kinetic pulse of the projectile.

If we look only at energy this can be fooling us for big ammo with slow vel!


----------



## Nicholson (Sep 25, 2012)

Yup, that's what dogbox and wll were explaining earlier :thumbsup:


----------



## wll (Oct 4, 2014)

Take a bowling ball going 100fps and a 124gr ball going 1200fps (NATO 9mm) One will put a hole through part of you and could kill you, the other will knock you through the living room wall .... it may not penetrate you but do some serious crushing damage.

Slingshots shoot mini bowling balls as they can't (as of yet, realistically) reach those higher velocities.

wll


----------



## August West (Jan 21, 2012)

I have been shooting animals with slingshots for the better part of 40 years, heavy works and light sucks. These types of debates are next to worthless when it comes to slingshots.


----------



## AnTrAxX (Jul 18, 2012)

One might also get a trauma when he listens to James Blunt for too long...so....just sayin´...


----------



## Jacktrevally (Feb 14, 2011)

Who's James Blunt? Is that the guy who lost love is Simona?


----------



## wll (Oct 4, 2014)

AnTrAxX said:


> One might also get a trauma when he listens to James Blunt for too long...so....just sayin´...


 :rofl: :rofl: :rofl:

wll


----------



## DogBox (Aug 11, 2014)

Jacktrevally said:


> This is where the kinetic pulse punch in. It shows that a slow vel projectile with great mass may have a relatively bigger momentum but lower energy whereas a fast moving light ammo may have less momentum but higher energy. The productb of energy and momentum gives an indication of the kinetic pulse of the projectile.
> 
> If we look only at energy this can be fooling us for big ammo with slow vel!


I'm sorry, I have lost the momentum of this thread... At first you ask - on here - what is 'blunt trauma'?, and then you come out with this stuff?

Could easily have Google searched.

"...this can be fooling us...!" :werd:


----------



## Jacktrevally (Feb 14, 2011)

Interesting from a member who joined us a couple of month ago!


----------



## POI (Dec 5, 2014)

love this stuff guys. I keep it simple using Ft/Lbs to compair setting on my Talon, Revo, and other Hi power airguns. Prob never got this deep because the projectiles are calibrated predetermined and not as variable. but for slinging balls of all types this is cool S#!%.

So much more to learn...

POI


----------



## Kerry Cornelius (Nov 11, 2014)

Not only does the penetration which kills the animal, but there is a shock wave which comes with the force of the weight and speed of the projectile when it hits the target that kills the animal as well. Some people refer to it as knock down power. This is why bullets are made out of lead because it is soft and mushrooms making a bigger shockwave and doing more damage. I hope this helps.


----------



## Jacktrevally (Feb 14, 2011)

This is called transfer of momentum, whivh from basic principle is the force!


----------

