Terminal Ballistics Testing

[Charles A]

The thread on the HAT bullets shot into phone books, and several others has once again brought to light most people's misunderstanding of wound ballistics and terminal ballistics testing.

First a short thought on testing with "Phone books".

To quote Dr. Roberts (one of the, if not the, foremost Ballistitian in the world) on different mediums for testing bullets, specifically paper-

"Calibrated 10% ordnance gel at 4 deg C; the other proposed simulants have NOT demonstrated adequate results compared to living tissue"

Unfortunately you can't use paper as a comparison between bullets either. Length, weight, jacket thickness, bullet composition, bullet type (IE.. plastic tip, hollow point, aluminum tipped, jacketed soft point, etc,), impact velocity, RPM's, yaw, etc., all combine to create variances in bullet performance; one bullet may expand/fragment violently in paper, yet perform poorly in tissue, and vice-versa.


If one just wants to test bullet upset, with no real idea of penetration depth or crush cavity, water is a much better medium.

Another quote from Dr. Roberts- "Water is a good test medium to assess bullet upset; many crime labs use water recovery tanks for that purpose. Be aware that water generally reveals the maximum upset which can occur to a projectile in soft tissue—your actual result in living tissue may be somewhat less"






Below are links to papers on wound ballistics that will be very beneficial to anyone trying to understand wounding effects in tissue by projectiles and/or those trying to test bullets themselves.

http://ammo.ar15.com/project/Fackler_Articles/Theodore_Kocher.pdf


http://ammo.ar15.com/project/Fackler_Articles/bullet_fragmentation.pdf


http://ammo.ar15.com/project/Fackler_Articles/effects_of_small_arms.pdf


http://ammo.ar15.com/project/Fackler_Articles/wounding_mechanism_projectile_shape.pdf


http://ammo.ar15.com/project/Fackler_Articles/wounding_mechanism_projectile_shape.pdf


http://www.rkba.org/research/fackler/wrong.html


http://ammo.ar15.com/project/Fackler_Articles/shock_wave_myth.pdf


Hope it helps,
Charles

 

[Buffalobob]

human skulls, both empty and filled with water

There's a joke in that quote, but you can fill it in yourself

deformation is the most critical determinant of its effects on the body

Wait a minute, have the fundamental laws of physics remained true and constant for over a hundred years. Who was that fool that said "energy of deformation is important"

So over a hundred years ago a guy shot spinning and non spinning bullets into some stuff and decided he didn't give a ratsass about spin but we still have to argue about it.

 

[goodgrouper]

Doggonitt. You'd think that because Utah is the number one consumer of gelatin products in the world, we would have a couple of cheap buys on gelatin to use for all of our bullet testing. But alas, it's still quite expensive, time consuming, and messy. However, the empty skull thing is an alternative. There seems to be a multitude of them around here.......


Well, rather than go to prison, I think I'll stick to what is cheap and works. But it would be more fun splattering gelatin all over the countryside than digging around in newspaper bins but oh well.

 

[Charles A]

Grin....

GG, I can appreciate what your trying to do, so maybe something, somewhere in the above, can help you, or at least help you with the limitations of different test mediums. It is unfortunate that properly calibrated Ballistic Gelatin is so hard to make/test as individuals, and that the people that do the testing, do it more for bullets suited to two-legged targets, then four-legged.... Though there is some overlap.......

About the best testing material the average person can get is the animals themselves, but most can not shoot enough to get a statistical sample thats meaningful....

 

[MontanaRifleman]

I think there are some unanswered questions. What effect does bullet spin have on terminal stability? What effect does stability have on terminal ballistic perfomance? Do different media have different effects with different bullets?

I really don't have a dog in this fight other than I would like to know the facts and see a good LR bullet developed.

I think the ultimate testing will come with actual hunting loads used on game and it may take a while to get good overall data. In the mean time, water jugs at actual ranges and velocities are probably the best mom and pop tests.

 

[RockyMtnMT]

Maybe a 50 gal garbage can full of water at distance? It would last a long time if you line it w/ a trash bag. Not so tough to hit at long range, and you don't have to worry about having the milk jugs in perfect line to catch it in the 4th, 5th, or 6th jug.

I think I heard this somewhere a while back. I think I'll have to try it.

Just another thought,... everyone has one.

Steve

 

[royinidaho]

Hey GG,

I'm working on a way to get some more pigs. Sows this time. I've learned that the large sows when butchered only the loins are taken along with the hams which are made into sausage.

Which leaves the whole front shoulder portion in one hunk. However there are no innards.

By the looks of the NAB on the big boar, effective range was something like 700 yds via a reduced load and spin didn't mean squat as far as bullet perfromance and straightness of wound channel went.

In fact the lilttle 115 gr 25 cal Berger after hitting major bones had a straight wound channel.

If I can get more than a couple sow's fronts I'll pack 'em in ice and give you a holler.

 

[MontanaRifleman]

I was thinking of using large elongated cardboard boxes lined with garbage bags and filled with water. Only problem is, you're not likely get more than one bullet per box of water, and a lot of water required.

 

[royinidaho]

I was thinking of using large elongated cardboard boxes lined with garbage bags and filled with water. Only problem is, you're not likely get more than one bullet per box of water, and a lot of water required.

When we did testing with water we used a 55 gal plastic barrel. We were doing pistol and rifle bullets. We achieved very poor performance with some bullets and contacted the manufacturer and was told that the plastic was a problem. I forget what was recommended but we have quit doing testing except on dead animals or live ones if I ever get lucky.

However the plate on that boar's shoulder was something I've never seen before. It was very thick and tough but was living tissue and nothing like the plastic barrel.

I'm wondering if scrap chap leather from the local saddle/chap shop would be a good front end.

Also if it were possible to rig a sealant, as the boar had (fat) which immediately sealed both entrance and exits except where there was a massive exit.

I've also been contemplating use auto oil Hell, I have everything else, I may as well have one of them there super fund sites.

Just had a major bolt of inspirationlight bulb I have some oil absorbent out of Canada. Its pretty cool stuff. Soaks up petroleum products and bio degrades it. After cleaning a spill I put the stuff in the compost pile and in a couple of years it goes on the garden.

I bet if I soaked the heck out of it with oil it would provide a pretty fair penetration test medium.

A hell of an idea. I'll do a small sample test in tomorrow. My huntin' vehicle needs an oil change anyway.

MontanaRifleman, thanks for the inspiration. You're a heck of a man. If this works it'll be more than reasonable for cost and reusable time and time again and eco friendly. Only problem will be retrieving the bullet.

Hmmmm, we'll see.

 

[RockyMtnMT]

Has anybody tried the Bullet Test Tube, it's in the Sinclair catalog. Says it can be reused. Then they have a thing to put on the end of it capture the bullet as well. It doesn't look very large, might be a tough shot very far out.

Steve

 

[MontanaRifleman]

Thanks Roy, as far as me being a heck of a guy, I know a few people who would vigorously debate you on that. But that oil soaking media sounds like a great idea. Will be real interested in the results.

The bullet test tube sounds like it might be a good for short and maybe medium range depending on easy/difficult it would be to hit. I was actually thinking of 6" or 8" PVC maybe 6 or 8 ft long.

 

[Charles A]

The Bullet Test Tube might be useful for comparing bullets, but like water it won't correlate to tissue.....



Roy, OIL???? grin......

 

[gahlizard]

been there, done that with the PVC. Not so good...you end up with pvc everywhere and if it is too close range, it gets pretty violent. the first foot or better is trashed a 100 yrds. had to swith over to a piece of schedule 20 ss from work. it is 8" with some elongated holes plasmaed into the top to get rid of a little water pressure. plastic is taped on the opening, the pipe is secured to saw horses and filled with water. pretty inpressive when you drop the hammer on her.

 

[MontanaRifleman]

Yeah, I was wondering if the force would shatter it...maybe 200 yds???