Ballistic Putty

[alexclarke]

I am interested in doing some research into the effects of air rifle pellets on animal tissue, how far do they penetrate, do hollow points make much difference, etc. etc. I am planning on testing the pellets at realistic distances (probably 10, 20 and 30 yards)

Where can I get some of the ballistic putty used for modelling the impact of bullets on human tissue?

If you want to suggest your favourite pellet brand for testing, please look at my other thread.

If you want to get involved then mail me, if any Devon shooters have a secluded spot where we can do it, that would be helpful too.

Alex

[fullmetaljacket]

You might find this link useful

http://home.hiwaay.net/~ispellan/PelletTest02.html

[alexclarke]

FMJ, thanks mate! That was the kind of thing I was hoping to do... certainly gives me some ideas. DO you spend all your time searching the internet for stuff like this??? <img src="http://jsramsbottom.co.uk/bbs/e/icon_confused.gif" alt="Confused" width="15" height="22"><!--graemlin:-->

Alex

[pneuguy]

...if you really want the results you get to have predictive value in the real thing (i.e., live quarry) then you'll need a more realistic ballistic tissue simulant than putty. Putty is much too dense (2 to 3x denser than tissue) and has weird mechanical behavior besides.

One cheap example of a good tissue simulant that I've used is wet (flooded) corrugated cardboard. Like meat, being mainly water, saturated cardboard has the right density and, unlike wet paper, seems to react better dynamically because (I speculate) the channels provided by the corrugation provides a path for the water to flow.

Anyway, the penetration (i.e., layers of cardboard) I got when using the stuff agreed well with both numeric simulation and experience with real game (rabbit, squirrel, and Australian myna bird).

The results match well the predictions of this online calculator...



Here's the link...

http://www.computer4me.com/airgunlin..._wchannel.cfm?

And some pic's of a cardboard experiment...





Steve

[fullmetaljacket]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Ale:
DO you spend all your time searching the internet for stuff like this???[/quote]

Recoil or torque, I probably like it, and I have a 24 hour connection at my disposal <img src="http://jsramsbottom.co.uk/bbs/e/icon_biggrin.gif" alt="Big Grin" width="15" height="15"><!--graemlin:-->

[fullmetaljacket]

some more links:

pellets or spherical shot:

http://www.pyramydair.com/site/artic...s-round-balls/



and since you're into terminal ballistics, this is an excellent resource:

http://www.mindspring.com/~ulfhere/b.../wounding.html

very technical and detailed, sometimes some sections are unaccessable due to bandwith limits

also the Firearms Tactical Institute:

http://www.firearmstactical.com/wound.htm

and a very good article on the Finnish gunwriters website:

http://guns.connect.fi/gow/QA15.html

scroll down to the title 'About wound ballistics' near the middle of the page.

should keep you busy for a few hours <img src="http://jsramsbottom.co.uk/bbs/e/icon_biggrin.gif" alt="Big Grin" width="15" height="15"><!--graemlin:-->

[alexclarke]

Thanks for the cardboard tip, I had presumed that ballistic putty had been designed to accuratly model flesh for this kind of test!

I have also used blocks of cold lard in the past, but on reflection I think that they are two soft/not fibrous enough...hmmm...

Alex

[alexclarke]

You lucky sod! <img src="http://jsramsbottom.co.uk/bbs/e/icon_wink.gif" alt="Wink" width="15" height="15"><!--graemlin:--> Ah well, I am having another pop at studenting next year, so I will be joining you at that game!

(I saw a post somewhere about you having fitness trouble/qualms with regards joining the army, mail me if you want a bit of help/advice. <img src="http://jsramsbottom.co.uk/bbs/e/icon_wink.gif" alt="Wink" width="15" height="15"><!--graemlin:-->)

Alex

[fullmetaljacket]

I'd be interested in any advice you have to offer. It's not that i'm not fit, I'm 5'11" and weigh 83 kg, most of which is beer gut <img src="http://jsramsbottom.co.uk/bbs/e/icon_rolleyes.gif" alt="Roll Eyes" width="15" height="15"><!--graemlin:--> and if I do apply to join the army, it won't be for another 9 months. I'm just not sure I have the stamina, I've been smoking regularly for 5 years now.

Anyways, back to the topic of penetration tests.

From the FBI study Handgun Wounding Factors and Effectiveness (which talks about pistols versus humans, but I think is relevant, as the truths of subsonic projectiles versus living targets also apply to airgun quarry):

"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, and, in the words of two of the participants in the 1987 Wound Ballistics Workshop, "too little penetration will get you killed." Given desirable and reliable penetration, the only way to increase bullet effectiveness is to increase the severity of the wound by increasing the size of hole made by the bullet. Any bullet which will not penetrate through vital organs from less than optimal angles is not acceptable. Of those that will penetrate, the edge is always with the bigger bullet."

It's worth reading the whole article, it might give you some pointers to what exactly your study hopes to achieve. From what I've understood, you're trying to compare the effects various pellets have on live quarry, therefore understanding how the pellet actually kills the target is imperative.

Eg, wound mechanisms from the article:

"(1) Penetration. The tissue through which the projectile passes, and which it disrupts or destroys.

(2) Permanent Cavity. The volume of space once occupied by tissue that has been destroyed by the passage of the projectile. This is a function of penetration and the frontal area of the projectile. Quite simply, it is the hole left by the passage of the bullet.

(3) Temporary Cavity. The expansion of the permanent cavity by stretching due to the transfer of kinetic energy during the projectile’s passage.

(4) Fragmentation. Projectile pieces or secondary fragments of bone which are impelled outward from the permanent cavity and may sever muscle tissues, blood vessels, etc., apart from the permanent cavity. Fragmentation is not necessarily present in every projectile wound. It may, or may not, occur and can be considered a secondary effect."

Just to make things a bit more scientific and complete <img src="http://jsramsbottom.co.uk/bbs/e/icon_wink.gif" alt="Wink" width="15" height="15"><!--graemlin:-->

[Phil Bulmer]

If you want to do the job properly then ballistic gel is the stuff to try. It's quite wobbly stuff and will simulate flesh quite accurately. The next best thing is soap, especially if you can get it in industrial sized blocks. It works well for small calibre projectiles travelling at subsonic speeds.
<img src="http://jsramsbottom.co.uk/bbs/e/icon_smile.gif" alt="Smile" width="15" height="15"><!--graemlin:-->

Phil

[LandRover]

Why don't you commit to eating chicken for a few weeks. Before you roast each bird up shoot it with your airgun at 25yds and 50yds!! Cut the chicken up and write down your results then cook away! Crazy, I know but what the heck!