ballistic gel test question

C0untZer0: said:
I think the problem that you still face is what equation / what values do you apply to any results you get.

Here is the why Duncan MacPherson's formula is used. It takes a lot of time and effort to create ordnace gel blocks. When the FBI did their tests, if a BB traveling at roughly 590 fps plus or minus 15 fps, penetrated less than 2.95" or more than 3.74" they discarded that block. They didn't use it for testing.

Actually I think that's still the FBI's policy - but they are a huge agency and they have the money to do that.

What Duncan MacPherson's formula allowed people to do, is take a block that doesn't meet the specifications, and still use it to get testing results. The bullet may penetrate more or less in the out-of-spec block, but based on the BB results - the test results for the bullet can be adjusted or normalized using MacPherson's formula.

MacPherson could take those same equations and create a table for some standard round - like Winchester Silvertip or something, but he hasn't.

To my knowledge, the only table available is for a BB traveling roughly 590 fps. As I said before MacPherson's table maxes out at 620 fps.

If you want test results that mean anything, you first have to have a way of propelling a BB at around 590 fps. Then you can start shooting it into your Knox gelatin to see if it is penetrating more shallow or more deeply than would be expected in ordnance gel and nail down the exact recipe needed for you Knox. Then when you've got a good recipe, you can run your tests and get good results. And your results will be validated by having a BB penetrate the gelatin roughly 3"
Click to expand...

MacPherson's model is a lot of fun to play with indeed.

It allows you to play "what if" for hours (at least for non-expanding projectiles, if you wanna play with JHPs you have to decide upon the diameter your round would expand to) once you get it set up on an Excel spreadsheet. (takes about 30-45 minutes to do it nicely)

Almost eliminates the need to actually shoot gelatin...:cool:
 
O.k., with a gel formula of one box (four pckgs of Knox) and one cup of water per box my ..45acp XTP 230gr. penetrated to 12.25" and expanded to .703". I might have mentioned in a different thread,but, I expect to move from the Northeast to the Southeast within the next few months. I believe feral hogs to be the most common predator I'm likely to run across while in the outdoors after I relocate and it seems that this performance will be adequate for any encounters. Of course input and opinions from more experienced shooters are always appreciated.
 
Did you use the +P ??

Here are test results from tnoutdoors9, using SIM-TEST gel:

http://www.youtube.com/watch?v=3Ct33tKvpKo

You'll notice he lists his BB calibration: 3.32"

14.75" of penetration, avg diameter of .653"

Normally the bullet from the +P version of the catrtridge penetrates less and expands more than the same bullet from the standard pressure version of the cartridge.

As far as stopping hogs, I guess it would depend on shot placement, but you could search hogdogs posts. I seem to remember Brent saying he'd cut .45 slugs (and assorted other stuff) out of the shield when butchering em.
 
"There is a debate about Knox gelatin being the equivilant of ordnance gelatin."

Knox is the primary manufacturer of ballistic gelatin in the United States although a number of others have popped up.

As I understand it, the primary difference between home gelatin and ballistic gelatin is that ballistic gelatin isn't food grade. It's not as refined.

And unless the Mythbusters crowd is doing something underhanded, the formula they use is the standard 10% ballistic gelatin.
 
I have killed a feral sow that weighed a bit more than 150lbs with a .45 ACP. It was already wounded by a muzzle loader but was able to scramble through the swamp in a hurry. The first shot from the .45 really took the sand out of it.
 
The load I used was 5.2gr of titegroup. I have no idea if this qualifies as a +P load. It was suggested to me by someone with alot more experience loading the acp than I do. The original recipe I had for gel was 1 1/2 cups of water per box of gelatin. I tried it and the load penetrated completely (17") and was not recoverable. The block of gel I used for the results I mentioned was 1cup water per box of gelatin. Bullet velocity was 865fps with this load. Entirely subjective but muzzle jump and felt recoil were no more than with factory ammo and actually seemed to be slightly less. All fired cases were recovered and no sign of excessive pressure was evident. I suspect my gel was of a thicker consistency than standard. Which I think would be O.K. as it may more closely mimic the muscle density of a feral hog. Again, I'm no expert. I have limited experience with the acp and none at all dealing with hogs.
 
The Winchester standard pressure Rangers propell a 230gr bullet to 895-905 ish.

Just to check, you're firing these out of a 5.03 in barrel (or close) ?

Your bullets are flying a little slower than that, - so I don't think you're creating a +P loading, your gellatin may be OK (who knows ?)
 
Last edited:
If you shoot through bone AND gelatin both you're very likely going to get distorted readings.

Gelatin is an analog for all tissue -- bone, muscle, fat, etc. -- combined. It simulates the average mean density of the body as a whole.

That's one of the primary reasons why it's become a nearly universal standard for bullet testing. You don't have to get into the esoteric mess of trying to cast bones into blocks of gelatin and figure out a way of making those results meaningful across a broad range of testing.
 
The gun used is an RIA 1911a1 match .45acp 5" bbl.

Mike Irwin: thanks for the info, I didn't know gel was meant to simulate more than muscle density.

COuntZero, based on your information I may increase my load from 5.2gr to 5.4gr. It doesn't seem pressure will be an issue and I'll test it in an identical block of gel to the one I listed results for.
Thanks, Bill
 
Last edited:
The proof of 10% ballistic gelatin's usefulness as a testing medium can be seen more and more clearly as rounds tested are used in actual shootings.

The two data sets tend to synch up quite well regarding terminal performance.

There have been a number of people over the years who have tried to "improve" gelatin data by casting in bones or bone substitute and then shooting.

The results have been, from what I've seen, less accurate overall when compared to actual shootings.
 
^ Yes


But just FYI Synbone AG of Switzerland makes all sorts of different bones.

http://www.synbone.ch/wEnglish/catalogue/categories.php?navanchor=1010007

Brassfetcher runs some tests with the bone plate in front of the gel block:

http://www.brassfetcher.com/PDF/38 Special JHP performance through Bone Simulant plates.pdf

Ordnance gelatin is a test medium that generally correlates to bullet effectiveness. I think you're better off using 10% ordnance gel and not putting pork ribs or bone plates in front of it if you want to get a general idea of how the bullet is going to perform.
 
Last edited:
I have to say though - I'd really like to use a Synbone skeleton, then fill the insides with form-fitting ordnance gel, and then test with heavy clothing / 4 denim test.

What I'd do with that data though - I have no idea what I'd do with that data, how to match it up with actual shootings, but it would still be cool.

But one of the things that I have read, I've read accounts of bullets being lodged in the shoulder bone, rear rib or lodged in the spine, and those same bullets flew out the back of a 16" block in the gellatin test.
 
Last edited:
"But one of the things that I have read, I've read accounts of bullets being lodged in the shoulder bone, rear rib or lodged in the spine, and those same bullets flew out the back of a 16" block in the gellatin test."

No two bullets will behave exactly the same, nor will bullets shot into test material completely synch up with what's seen in actual shootings.

That's a simple impossibility to achieve.

Differences in guns, gun barrels, velocities, and myriad other things all conspire to make real life a LOT more complex and variable than the rigorously controlled conditions that are found in the lab.
 
Well it makes me wonder..

In a test - a bullet that flys out the back of a block of gel (usually not JHP), but in some report, a guy shot with the same thing ends up with it lodged between ribs in his back or something...

I wonder if they shot that round into a "block" of gel enclosed in a Synbone skeleton if that bullet would end up lodged in the back of the Synbone model also.

So many people are worried about over-penetration, that if they're firing anything more powerfull than 380 - if it comes out the back of a 16" gel block it almost automatically gets discounted for SD use, and maybe some of those rounds that sail on through, would not sail through an actual assailant, nor would they sail completely through a Synbone skeleton with ordnance gel guts.

Just makes me wonder...

Unlike 9ballbilly I have no where to actually test a Synbone Jeleton - if I did , I'd make one. I think it'd be cool.
 
Remember, we're talking about gelatin portraying the AVERAGE mean density of all tissues found in the human body.

When shooting into an actual living target things are going to be different from a terminal ballistics standpoint simply because you no longer have a consistent average mean density through the target, you've got depending on the person, lots (or not) of low density fat, lots (or not) medium density muscle, and a fairly consistent from target to target amount of high density tissue in the form of bone.

Because of those transitions from low to medium to high of course there are going to instances in which the bullets stop against a bone. That could be caused by many things -- a jacket flaw causing the bullet to open much faster than other bullets, the bullet being slowed by something before hitting the target, the bullet being fired from a gun that doesn't develop the same velocity as the one used in the gelatin test, or myriad other things.

If laboratory testing in gelatin truly provided the whole picture of how a bullet behaves once it's fired into a living target, there simply would be no need to compare and verify street shooting performance with laboratory performance.

So, once again, don't read too much into one or two examples, examine the results when taken as a whole -- BOTH laboratory testing AND street experience. Then you'll approach the true picture of how a bullet behaves once it impacts a target.
 
You must log in or register to reply here.
Back
Top