Home-made ballistic gelatin

[Zhukov]

I guess this is mostly a question for DocGKR, but is there a difference between the type 250 ballistic gelatin that Vyse sells versus the unflavored gelatin packets you can find on the internet and in grocery stores? I was thinking of making some one of these days, but don't want to get into a big dollar outlay while playing around with it.

[DocGKR]

Not the same...

[Zhukov]

Not the same...

Bummer. Have you ever seen how different the results are between plain old grocery store gelatin and the real deal? Looks like Vyse is selling ballistic gelatin for a reasonable price on their website, and per pound it's actually reasonable. If the economy improves and I have some spare change, I might order a batch from them.

BTW - what's the recommended block size for rifle shots?

[sff70]

Can't answer the question about block sizes, but having observed FBI protocol gelatin testing in person on 2 occasions (one at BRF, the other by an ammo vendor) . . .

. . . the gelatin has to be mixed correctly, then poured into a mold and cooled to a specific temp.

Prior to use, the gelatin has to be checked to ensure it is within spec (by firing a specific weight and diameter bb with a specific velocity range and checked with a chronograph) and that must penetrate to a specific depth range.

Then, the gelatin must be used quickly enough so it doesn't warm up and throw off the results.

All the above requires a lot of equipment that the avg person does not own nor is inclined to buy.

Some ammo vendors (Dooley Entreprises being one) will conduct testing IAW the FBI protocol at LE agencies. If you are LE and in the CA/OR/WA/ID/NV/AZ area, you might want to contact them to see if/when they will be in your area.

If you can't do your own testing, or observe it in person, Federal Cartridge Co, for one, has photos of FBI protocol gelatin testing that you can refer to on its web site.




After typing all the above, I found the following with a web search:

The test media used by the FBI to simulate living tissue is 10% Ballistic Gelatin (Kind & Knox 250-A), mixed by weight (i.e., one pound of gelatin to 9 pounds of water). The gelatin is stored at 4° Centigrade (39.2° Fahrenheit) and shot within 20 minutes of being removed from the refrigerator. The temperature of the gelatin is critical, because penetration changes significantly with temperature. This specific gelatin mix was determined and calibrated by the U.S. Army Wound Ballistics Research Laboratory, Presidio of San Francisco, to produce the same penetration results as that obtained in actual living tissue. The 10 % gelatin has been correlated against the actual results of over 200 shooting incidents. Each gelatin block is calibrated before use to insure its composition is within defined parameters. Copies of the test protocol are available upon request for those interested in duplication the testing or reviewing the procedures in greater detail.

The gelatin blocks for handgun rounds are approximately six inches square and 16 inches long. As necessary, additional blocks are lined up in contact with each other to insure containment of the bullet's total penetration. Each shot's penetration is measured to the nearest 0.25 inch. The projectile is recovered, weighed, and measured for expansion by averaging its greatest diameter with its smallest diameter.

The Ammunition Test Protocol using this gelatin is composed of eight test events. In each test event, five shots are fired. A new gelatin block and new test materials are used for each individual shot. The complete test consists of firing 40 shots. Each test event is discussed below in order. All firing in these eight tests events is done with a typical service weapon representative of those used by law enforcement. The weapon used is fully described in each test report.

Test Event 1: Bare Gelatin The gelatin block is bare, and shot at a range of ten feet measured from the muzzle to the front of the block. This test event correlates FBI results with those being obtained by other researchers, few of whom shoot into anything other than bare gelatin. It is common to obtain the greatest expansion in this test. Rounds which do not meet the standards against bare gelatin tend to be unreliable in the more practical test events that follow.
Test Event 2: Heavy Clothing The gelatin block is covered with four layers of clothing: one layer of cotton T-shirt material (48 threads per inch); one layer of cotton shirt material (80 threads per inch); a 10 ounce down comforter in a cambric shell cover (232 threads per inch); and one layer of 13 ounce cotton denim (50 threads per inch). This simulates typical cold weather wear. The block is shot at ten feet, measured from the muzzle to the front of the block.
Test Event 3: Steel Two pieces of 20 gauge, hot rolled steel with a galvanized finish are set three inches apart. The steel is in six inch squares. The gelatin block is covered with Light Clothing and placed 18 inches behind the rear most piece of steel. The shot is made at a distance of 10 feet measured from the muzzle to the front of the first piece of steel. Light Clothing is one layer of the above described T-shirt material and one layer of the above described cotton shirt material, and is used as indicated in all subsequent test events.

The steel used is the heaviest gauge steel commonly found in automobile doors. This test simulates the weakest part of a car door. In all car doors, there is an area, or areas, where the heaviest obstacle is nothing more that two pieces of 20 gauge steel.
Test Event 4: Wallboard Two pieces of half-inch standard gypsum board are set 3.5 inches apart. The pieces are six inches square. The gelatin block is covered with Light Clothing and and placed 18 inches behind the rear most piece of gypsum. The shot is made at a distance of ten feet, measured from the muzzle to the front of the first piece of gypsum. This test event simulates a typical interior building wall.
Test Event 5: Plywood One piece of three-quarter inch AA fir plywood is used. The piece is six inches square. The gelatin block is covered with Light Clothing and placed 18 inches behind the rear surface of the plywood. The shot is made at a distance of ten feet, measured from the muzzle to the front surface of the plywood. This test event simulates the resistance of typical wooden doors or construction timbers.
Test Event 6: Automobile Glass One piece of A.S.I. one-quarter inch laminated automobile safety glass measuring 15x18 inches is set at an angle of 45° to the horizontal. The line of bore of the weapon is offset 15° to the side, resulting in a compound angle of impact for the bullet upon the glass. The gelatin block is covered with Light Clothing and placed 18 inches behind the glass. The shot is made at a distance of ten feet, measured from the muzzle to the center of the glass pane. This test event with its two angles simulates a shot taken at the driver of a car from the left front quarter of the vehicle, and not directly in front of it.
Test Event 7: Heavy Clothing at 20 yards This event repeats Test Event 2 but at a range of 20 yards, measured from the muzzle to the front of the gelatin. This test event assesses the effects of increased range and consequently decreased velocity.
Test Event 8: Automobile Glass at 20 yards This event repeats Test Event 6 but at a range of 20 yards, measured from the muzzle to the front of the glass, and without the 15° offset. The shot is made from straight in front of the glass, simulating a shot at the driver of a car bearing down on the shooter.
In addition to the above described series of test events, each cartridge is tested for velocity and accuracy. Twenty rounds are fired through a test barrel and twenty rounds are fired through the service weapon used in the penetration tests. All velocities are measured and reported.

Two ten-shot groups are fired from the test barrel, and two from the service weapon used, at 25 yards. They are measured from center to center of the two most widely spaced holes, averaged and reported.

Test barrel results demonstrate a round's potential independent of any weapon factors which can affect performance. Test barrel results are the purest measure of inherent capability for accuracy and velocity. Repeating these tests with a service weapon shows how well the cartridge/weapon combination may realize that potential.

[DigMe]

Also, Doc has posted this as a sticky here:

https://www.m4carbine.net/showthread.php?t=26028

brad

[Zhukov]

Guys - I'm well aware of how BG is prepared/used. My question was only about the difference between plain grocery store gelatin and 250A ballistic gelatin.

[PRGGodfather]

Definitely not trying to step on any toes here, but there is an interesting reasonably low-cost alternative for the home ballistician.

Perma-gel is reusable, solid at room temperature, and is crystal clear. I've used it for television shows, and can be calibrated with a BB to the same specifications as 10% ordnance gelatin.

http://www.perma-gel.com/

Perma-gel can be purchased at Cabela's for about $180, to include the oven and mold. Just pour it slowly down a stick to avoid bubbles, and the cost savings is from its ability to be re-melted and reused.

www.cabelas.com

We've used and reused it, and it can poured into just about any mold you choose, if you have a large enough supply...

[Zhukov]

Definitely not trying to step on any toes here, but there is an interesting reasonably low-cost alternative for the home ballistician.

Perma-gel is reusable, solid at room temperature, and is crystal clear. I've used it for television shows, and can be calibrated with a BB to the same specifications as 10% ordnance gelatin.

<snip>

Perma-Gel is not an acceptable substitute. Doctor Roberts has mentioned that it's OK for testing body armor, but it doesn't accurately model living tissue like BG does.

[PRGGodfather]

Okay!

[MK108]

Zhukov,

your question interested me so while testing gelatin blocks with other gelatin powders than the ones you use overseas I manufactured a little block(..whose volume was about 1/2 liter..) of 10% (..in weight..) animal gelatin using gelatin sheets for pies that you can find here (..in Italy..) in the stores...

...for the manufacturing I used the guidelines of the gelatin manufacturer together with the ones written by my friend Shawn Dodson...after that I tested the retardation properties of this gelatin block using an .177" air pistol loaded with 4.50mm diameter round lead pellets (0.52 grams each) whose impact velocities were about 110 m/s(..the variation was about 1 m/s between the five pellets..)....I shot five pellets and they entered to the right of the pic...the block temperature was 4 celsius degrees....if this gelatin had similar retarding properties of perfectly calibrated 10% BG I expected a penetration of a bit more than 6 cm(...so more or less the pellets grouped in the middle of the gel block..)....but, as the scale graduated in cm shows, the pie gelatin I was able to test using the percentage and temperature above clearly had less "strenght" than 10% BG...

http://img221.imageshack.us/img221/7733/questa2.th.jpg (http://img221.imageshack.us/i/questa2.jpg/)

http://img216.imageshack.us/img216/1310/questa.th.jpg (http://img216.imageshack.us/i/questa.jpg/)

http://img530.imageshack.us/img530/5635/questa3.th.jpg (http://img530.imageshack.us/i/questa3.jpg/)

All the best
Andrea

P.S.: a note...for pies the manufacturer suggests a 2.5% weight of gelatin sheets...so 1/4 of the block above....

[Zhukov]

Thanks for the work you did in compiling that data. Seems like the difference in commercial gelatin versus BG is too big to make it worth much of anything. Oh well...

[Shawn Dodson]

An interesting web page: How to Make Your Own Ballistic Gel (I'm not endorsing this technique, I'm just throwing it out for consideration: http://www.myscienceproject.org/gelatin.html

[DocGKR]

Uh...no.

[Shawn Dodson]

An interesting web page: How to Make Your Own Ballistic Gel (I'm not endorsing this technique, I'm just throwing it out for consideration: http://www.myscienceproject.org/gelatin.html

My remark would've been more appropriate if I'd said: "...I'm just throwing it out for fun...."

Doh!

[Glock17JHP]

BTW - what's the recommended block size for rifle shots?

I seem to recall 8 X 8 X 16 inches as being the standard block size...

For rifles/shotgun slugs you may need 2 blocks end-to-end...

[DocGKR]

There is no standard block size necessarily--you are describing the FBI type handgun blocks that are 20 lbs. The minimum size we use is 40 lbs.

[Glock17JHP]

Guys - I'm well aware of how BG is prepared/used. My question was only about the difference between plain grocery store gelatin and 250A ballistic gelatin.

If you contact Knox, they have a gelatin 'booklet' they can send you. I got one from them back when the IWBA was trying to figure out a gelatin issue involving pig ribs inserted into gelatin blocks where the gelatin was getting 'watery'... This booklet had all kinds of information, and they even attached a business card so I could call and ask them questions if necessary...

[Glock17JHP]

There is no standard block size necessarily--you are describing the FBI type handgun blocks that are 20 lbs. The minimum size we use is 40 lbs.

How big are they dimensionally? Are they used for rifles/shotgun slugs?

[Shawn Dodson]

I had three stainless steel gelatin molds fabricated by a local HVAC/sheetmetal shop to cast gelatin blocks in the following dimensions:

6x6x16 (9 liters water, 1 kg gelatin powder)
8x8x18 (18 liters water, 2 kg gelatin powder)
10x10x18 (27 liters water, 3 kg gelatin powder)


I had the molds constructed so the surface of the gelatin solution is 1.5 inches below the rim of the mold.

After some experience with the other two molds I modified my plans for the 8x8x18 gelatin mold to have the walls gradually taper, increasing in width from bottom to top to facilitate ease of gelatin block removal. The other two molds have a straight wall design which frustrates removal. The 8x8x18 became my favorite size for testing handgun ammunition. The large mold is for rifle cartridges and the small mold is for small caliber cartridges (.22 thru .380).

[geminidglocker]

For the price of some of the pre-formed gelatin things, I can buy three goats. They are a much better gauge of terminal ballistic performance. I have yet to put one in a vehicle though, for the auto-galss test. See, that would get expensive as different angles, multiple vs. single hits, the smell of the vehicle after two or three goats, etc:.....:rolleyes:
I guess if you're gonna use ballistics gelatin at least stick some bones in it.

[Shawn Dodson]

I guess if you're gonna use ballistics gelatin at least stick some bones in it. If this were the case, what bones? Where along the bullet track (near the beginning, middle or end) should the bone be located? What part of the bone should be targeted? How will this information be of practical value?

Given the variables of any particular shooting, precision shot placement and wound path through the body cannot be controlled by the shooter. Terminal performance involving bone is what it is.

[geminidglocker]

If this were the case, what bones? Where along the bullet track (near the beginning, middle or end) should the bone be located? What part of the bone should be targeted? How will this information be of practical value?

Given the variables of any particular shooting, precision shot placement and wound path through the body cannot be controlled by the shooter. Terminal performance involving bone is what it is.

My point exactly. Why use ballistics gel? But in all seriousness, my post was just meant to be funny, as well as intelligent.

[DocGKR]

Gelatin block weight and size are dependent on the projectiles that will be tested. It is critical that the block size be large enough to fully capture the projectile track, including any fragments, and stretch—one can place a second block behind the primary block in order to capture deep penetrating projectiles, however the blocks must be intimately in contact, with no air gap. Small 20 lb blocks can be used for handgun projectiles, 40 lbs blocks can be used for 5.56 mm projectiles, while 60-80+ lbs blocks are needed for larger rifle calibers. We use 66 liter rectangular plastic storage bins as molds for blocks in the 40-100 lbs weight range; size if roughly 20x14x5-10" depending on weight.

geminidglocker--Your posts don't make sense; please clarify.

[Shawn Dodson]

I'm not a "Pro". Nor do I have a college degree. I'm just a Regular Joe who's a student of wound ballistics. So feel free to argue with me all you want! LOL

I can understand the rationale for the Red Cross DVD to present medical information showing complexities of wound trauma produced when a bullet encounters bone.

From the standpoint of selecting a bullet to quickly stop deadly violence – we’re just making holes, be it soft tissue or punching through bone. The goal is to damage tissues critical to immediate survival. These tissues are all soft tissues.

[Glock17JHP]

David...

Polyurethane is not a good material to model bones with... I think...

Pig bones (human sized) would be much better (since human bones are harder to get)...

[BushmasterFanBoy]

geminidglocker--Your posts don't make sense; please clarify.

To the untrained eye, it would seem to make a lot of sense to just skip to the chase and just test rounds intended to be used against living animals, on, well.... living animals. I'm sure to the more anatomically astute, that might seem like comparing apples and oranges, but to me at least (and I'm guessing gemindglocker as well) it seems like a closer test than just using gelatin. :confused:

[Jim from Houston]

But see, the key is that the "untrained eye" doesn't really understand the process.

The reason that properly calibrated (and that's key) ballistic gelatin is used to test is not based on some sort of hypothetical discussion of "gee, what is a better simulant, gelatin or a goat?"

It's used because over decades of experimentation AND comparison with real world shootings, researchers have been able to establish scientific proof that properly calibrated ballistic gelatin is indeed an excellent predictor of what bullets do in the real world.

All of this is much less hypothetical than people who oppose ballistic gelatin testing want to make it sound...researchers have a keen interest in real world shooting incidents (provided they are PROPERLY documented) as well as ballistic gelatin testing.

But what you find when you compare the two, is that the properly calibrated gel is indeed an excellent predictor.

Look-up the work of Eugene Wolberg if this sort of research interests you further. In short, he researched actual shooting incidents of the San Diego Police and found that their rounds in the field performed as gelatin tests would predict.

With regard to putting bones in gelatin, if anyone's interested in this and isn't familiar with the Dahlstrom and Powley Royal Canadian Mounted Police tests, here's a link to a summary:

http://www.css.drdc-rddc.gc.ca/cprc/tr/tr-1995-01.pdf

The Mounties tested with swine rib bones embedded in gelatin blocks...to make a long story short, they found that rib bones don't have a large impact on the terminal performance of defensive rounds. Ribs, of course, are some of the flimsier bones, so long bones like femur, etc. would no doubt have much more of an impact, but ribs are what you find in the normal firearms target zone. Shooting at the skull, of course, can be challenging for a number of reasons.

[Glock17JHP]

A few comments on gelatin may be in order at this point, also...

Gelatin is especially good to use because it is HOMOGENOUS. Some are thinking right now that HOMOGENOUS is not good because the human body (the 'target') is NOT homogenous. That is true. However... if you AVERAGE all of the typical shots into the human body, they will match properly prepared gelatin in penetration depth, and the expanded bullet characterisics overall. When a scientific study is done, you need a 'control' (a constant) so you are comparing apples to apples. The homogenous properties of properly prepared gelatin give us that 'control'. Human gunshots wounds (and comparable animal gunshot wounds) back up the gelatin data, but are much less CONSISTENT. This is why gelatin needs to be a major contributor to wound ballistics testing... it has CONSISTENTCY. Using actual shooting data exclusively (human or animal) will result in data with such a wide amount of 'scatter' that it will be much harder to gain usefull information from it from a comparison viewpoint. Gelatin use allows comparison between shots to a much, much larger degree... and this will yield much more useful data overall. This does not mean actual shots into humans or comparable animals are NOT important, it only stresses the importance of gelatin use for wound ballistics. Neither gelatin or actual shooting data should be used to the exclusion of the other... BOTH have their places.

I hope this makes sense...