SpudFiles

JoergS wrote:I will be wearing a motorcycle helmet and protective gear all around. I am not THAT crazy.

The construction will be made out of steel 100%.

Jörg

I hope you'll be wearing a cup as well? All I can see is a slight slip of the band followed by a high-pitched squealing...

Ya gotta protect yer nuts!

That sounds like a pretty titanic effort to still only get the same energy as a .22 pistol.
Nonetheless, don't let me dissuade you from trying to do it...

JoergS wrote:If my calculations are right, the draw force (at 500% elongation) will be about 110 kilogramms (240 lbs).

I can't help but have a certain quote appear in my head:
"If my calculations are correct, when this baby hits 88 miles per hour...you're gonna see some serious s***."

Ragnarok wrote:That sounds like a pretty titanic effort to still only get the same energy as a .22 pistol.[/i]

Well, the energy may be the same, but the stopping power of a lead ball in .91", flying at 200 km/h, will certainly be much superior to a .22.

JoergS wrote:Well, the energy may be the same, but the stopping power of a lead ball in .91", flying at 200 km/h, will certainly be much superior to a .22.

It would certainly be a formidable missile but the higher velocity and smaller frontal area of a 22 bullet would allow much deeper penetration, so in terms of lethality I don't think you could categorically say it will be superior against living tissue without appropriate testing.

And that is of course no problem because harming living tissue and talking about it is against forum rules.

He also said stopping power, not lethality. If I may add, a 140 grains 9mm parabellum has more stopping power than a 40 grains .22 WMR , for roughly the same muzzle energy (419 - 439 joules) .

So I guess, that Joerg is right. Stopping power will be higher, even if if doesn't penetrate as deep/at all.

I think I have been very diligent in terms of appropriate tests.

Here are some examples:

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Video's embedded by jrrdw.

wow.. that's really impressive
now about 'Slingshot vs. Coconut' vid... first of all, that's a nice pair of boobs

secondly, isn't that device considered as a trigger mechanism ??

JoergS wrote:Well, the energy may be the same, but the stopping power of a lead ball in .91", flying at 200 km/h, will certainly be much superior to a .22.

On a one shot basis, I'd agree. But if we're extending the comparison beyond simply energy, that .22 pistol offers the opportunity for rapid follow-up shots, and quite a lot more practicality.

Even with that said, I'm still interested to see the results of your tests.

...and quite a lot more practicality....

Not necessarily:
legality, weight, simplicity, enjoyment (which is a matter of personal taste), cost, etc.,etc..

Besides (IMO), that's like comparing, IDK, tomatoes to bananas or such.
Two different things.
Similar (firearm etc.) comparisons could be made about many spudguns but it's not really merited IMO.

BTW, Hope to see a vid of the test! 8)

EDIT: Little perturbed my entire reply with (spam) I saw yesterday got ...earlier.

Edited by jrrdw.

CpTn_lAw wrote:And that is of course no problem because harming living tissue and talking about it is against forum rules.

This is a purely academic discussion as opposed to "omg I shot the neighbour's cat with my spuddy haha!" so no harm there.

He also said stopping power, not lethality. If I may add, a 140 grains 9mm parabellum has more stopping power than a 40 grains .22 WMR , for roughly the same muzzle energy (419 - 439 joules).

If the 9mm is FMJ and the 22 is a hollowpoint, that would probably even out

So I guess, that Joerg is right. Stopping power will be higher, even if if doesn't penetrate as deep/at all.

The problem is defining "stopping power". Imagine getting hit by a bullet from an AK while wearing a bulletproof vest, all that kinetic energy is transferred to you (over 2000 joules) but it certainly won't kill you and might not even knock you down. A 22LR bullet with around 5% of that energy hitting you in the heart will definitely stop you. With a complex target like living tissue, shot placement is critical.

According to the FBI:

Kinetic energy does not wound. Temporary cavity does not wound. The much discussed "shock" of bullet impact is a fable and "knock down" power is a myth. The critical element is penetration. The bullet must pass through the large, blood bearing organs and be of sufficient diameter to promote rapid bleeding. Penetration less than 12 inches is too little.

JoergS wrote:I think I have been very diligent in terms of appropriate tests

Acknowledged and appreciated, so looking forward to your results for this one

Guys, this thread is going in the wrong direction. I want to perform a perfectly safe attempt to break a record for slingshots, with no harm to anything except a heap of towels as a backstop, and here we are discussing penetration into human flesh.

I am afraid that this threat will be closed by the admins if we go on, so please come back to the topic.

Jörg

You brought "stopping power" into the equation but granted, lets stick to velocity and weight measurments and energy calculations

No probs, and ...GOD JSR, your argumentation was good....

Nice vids Joerg, really looking forward to seeing your end product, or simple prototype, or whatever material you have concerning it

Made it!

56,64 Meters per second (185,5 fps) with the 82 gramms (1312 grains) .91 lead ball!

That is 131,53 Joules of energy.

I think I am the current world record holder for portable one man operated slingshots.

The video will follow.

Hooray!

Fork in hell! Is the rig bolted to the ground as well or held only by your feet?

Any ballistic gelatin tests to follow?