Primary & Secondary Deep Dive into Handgun Bullets

[Tokarev]

The panel discusses aspects of pistol bullets.

Three hours so listen at 1.25x or 1.5x speed:



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[feudist]

I watched that Saturday and was struck by 2 things.
One was that according to Fricke the Border Patrol sets minimum penetration at 8 inches in ordnance gel and only tests auto glass, 4 layer denim and bare gel.The other was Haggard stating that for non expanding bullets the Clear Ballistics gel does fine.
Thoughts on that?

[the Schwartz]

I watched that Saturday and was struck by 2 things.
One was that according to Fricke the Border Patrol sets minimum penetration at 8 inches in ordnance gel and only tests auto glass, 4 layer denim and bare gel. The other was Haggard stating that for non expanding bullets the Clear Ballistics gel does fine.
Thoughts on that?

Your question regarding the ability of the Clear Ballistics gel product to correctly represent the performance of non-expanding bullets strikes directly at why shear-validation of gelatin test mediums is so important.

As you are probably already aware, correct shear validation of 10% concentration ordnance gelatin requires that a 4.5mm steel BB* (having a nominal mass of 5.25 grains) must be fired at a velocity of 591 �± 13 fps into a gelatin block held at a temperature of 4ºC (≈39ºF). In order to validate a block's shear response in that velocity regime, the BB must penetrate to a depth of 8.5 ± 0.40cm in the gelatin block. Otherwise, the block must be discarded or, if used, a correction formula must be used to normalize the penetration data to the standard. The reason that this test is important is that it confirms that the gelatin test medium will correctly represent the shear forces that bullets will encounter in the 'low velocity' regime (generally taken to be <500 fps for FMJs) which effect penetration depth of the bullet near the end of its path in the gelatin where velocities drop into that regime.

Near the end of John Ervin's (BrassFetcher) video here—



—a brief tabular assessment of the results of the BB shear validation test for both 10% ordnance gelatin and the Clear Ballistics Gel product is provided.



Contrary to the manufacturer's claims that their product complies with the BB shear validation test protocol across a wide range of temperatures, the Clear Ballistics gel product consistently fails to correctly validate due to its significantly lower density and inferior response to low velocity strain rate. In the case of non-expanding bullets, the improper representation of shear forces by the Clear Ballistics gel in the low velocity regime means that non-expanding bullets will tend to penetrate significantly deeper than they would in 10% ordnance gelatin.

Insofar as the statement that the Clear Ballistics gel product ''does fine'' for non-expanding bullets, while the Clear Ballistics gel will inaccurately represent the maximum terminal penetration depth of FMJs (assuming that the FMJ remains in stable nose-forward flight for the entirety of its passage through the gel block), it will certainly demonstrate that FMJs and other non-expanding bullets are capable of deep penetration. Where amateur testing is involved, I think that Chuck Haggard's assessment of ''just fine'' is the equivalent of the ''good enough'' found in the quote, ''Perfect is the enemy of good enough'', commonly attributed to Voltaire.

Where truly accurate testing is desired, either of the two proven tissue simulants (10% ordnance gelatin and water) will suffice.

Finally, it is worth notice that, including the 3-part series written by Mike Wood in the online magazine, Police-One, there are presently no less than three independent sources who've discounted the claims made by Clear Ballistics Gel, LLC that their product 1.) shear validates correctly when a BB is fired into it at 591 ± 13 fps, and 2.) accurately represents the terminal ballistic behavior (specifically, projectile expansion and maximum penetration depth which are inextricably interdependent) of projectiles especially at lower velocities:

1.) PoliceOne/Mike Wood: https://www.policeone.com/police-pro...kEYB93TAd5o6J/

2.) Brassfetcher/John Ervin: https://www.youtube.com/watch?v=5pqPBnSYTIc

3.) TheChoppingBlock/Andrew Butts: https://www.youtube.com/watch?v=xJF-...ature=emb_logo

In the end, I find myself in very strong agreement with Dr. Roberts' assessment of Clear Ballistics gel as a test medium:

Clear Ballistic Gel is not a "consistent and controllable medium".

It is quite utterly useless from a terminal ballistic analysis perspective.

*BBs are chosen for this utility because they are non-expanding projectiles incapable of introducing yaw effects because they always present the same shape regardless of their axial orientation during their penetration through the ordnance gelatin.

[feudist]

Your question regarding the ability of the Clear Ballistics gel product to correctly represent the performance of non-expanding bullets strikes directly at why shear-validation of gelatin test mediums is so important.

As you are probably already aware, correct shear validation of 10% concentration ordnance gelatin requires that a 4.5mm steel BB* (having a nominal mass of 5.25 grains) must be fired at a velocity of 591 �± 13 fps into a gelatin block held at a temperature of 4ºC (≈39ºF). In order to validate a block's shear response in that velocity regime, the BB must penetrate to a depth of 8.5 ± 0.40cm in the gelatin block. Otherwise, the block must be discarded or, if used, a correction formula must be used to normalize the penetration data to the standard. The reason that this test is important is that it confirms that the gelatin test medium will correctly represent the shear forces that bullets will encounter in the 'low velocity' regime (generally taken to be <500 fps for FMJs) which effect penetration depth of the bullet near the end of its path in the gelatin where velocities drop into that regime.

Near the end of John Ervin's (BrassFetcher) video here—



—a brief tabular assessment of the results of the BB shear validation test for both 10% ordnance gelatin and the Clear Ballistics Gel product is provided.



Contrary to the manufacturer's claims that their product complies with the BB shear validation test protocol across a wide range of temperatures, the Clear Ballistics gel product consistently fails to correctly validate due to its significantly lower density and inferior response to low velocity strain rate. In the case of non-expanding bullets, the improper representation of shear forces by the Clear Ballistics gel in the low velocity regime means that non-expanding bullets will tend to penetrate significantly deeper than they would in 10% ordnance gelatin.

Insofar as the statement that the Clear Ballistics gel product ''does fine'' for non-expanding bullets, while the Clear Ballistics gel will inaccurately represent the maximum terminal penetration depth of FMJs (assuming that the FMJ remains in stable nose-forward flight for the entirety of its passage through the gel block), it will certainly demonstrate that FMJs and other non-expanding bullets are capable of deep penetration. Where amateur testing is involved, I think that Chuck Haggard's assessment of ''just fine'' is the equivalent of the ''good enough'' found in the quote, ''Perfect is the enemy of good enough'', commonly attributed to Voltaire.

Where truly accurate testing is desired, either of the two proven tissue simulants (10% ordnance gelatin and water) will suffice.

Finally, it is worth notice that, including the 3-part series written by Mike Wood in the online magazine, Police-One, there are presently no less than three independent sources who've discounted the claims made by Clear Ballistics Gel, LLC that their product 1.) shear validates correctly when a BB is fired into it at 591 ± 13 fps, and 2.) accurately represents the terminal ballistic behavior (specifically, projectile expansion and maximum penetration depth which are inextricably interdependent) of projectiles especially at lower velocities:

1.) PoliceOne/Mike Wood: https://www.policeone.com/police-pro...kEYB93TAd5o6J/

2.) Brassfetcher/John Ervin: https://www.youtube.com/watch?v=5pqPBnSYTIc

3.) TheChoppingBlock/Andrew Butts: https://www.youtube.com/watch?v=xJF-...ature=emb_logo

In the end, I find myself in very strong agreement with Dr. Roberts' assessment of Clear Ballistics gel as a test medium:









[B]*[/B]BBs are chosen for this utility because they are non-expanding projectiles incapable of introducing yaw effects because they always present the same shape regardless of their axial orientation during their penetration through the ordnance gelatin.

Thanks for that. I didn't realize tumbling was why BBs were used.

It apears that Brassfetcher's results directly contradicts where Haggard stated that Clear Ballistics overstates penetration at the cost of understating expansion.

Here's a follow on question: You typically see 3 to 5 bullets shot into a gel block. How many different blocks does it take to generate confidence in the resulting averages?

[the Schwartz]

[/COLOR]

Thanks for that. I didn't realize tumbling was why BBs were used.

Correct. No matter how a BB rotates about any given axis or even multi-axially, it is always a sphere. Because the BB is composed of a fairly strong steel alloy, it doesn't deform at the very low pressures that it encounters in the low velocity regime.

It apears that Brassfetcher's results directly contradicts where Haggard stated that Clear Ballistics overstates penetration at the cost of understating expansion.

No, sir, Chuck essentially got it right in the video and he clearly demonstrates a grasp of the deficiencies of the Clear Ballistics Gel product.

Check the video starting at 2:16:50.

Here's what Chuck said in his comparison of terminal ballistic performance (expansion, penetration, etc.) of bullets in 10% ordnance gelatin to that observed in Clear Ballistics Gel:

''Then it folds the mushroom against the shank of the bullet a little bit harder so what you end up with is less of an expanded diameter and if you have less of an expanded diameter you're going to get more penetration...''

That pretty much sums it up.

Here's a follow on question: You typically see 3 to 5 bullets shot into a gel block. How many different blocks does it take to generate confidence in the resulting averages?

As with any statistical experiment, larger data sets—generally speaking—result in higher confidence levels (expressed as P = 1 - α where α is error) that support conclusions drawn using that data.

The number of data (n) that meets an informal definition of 'minimum' is usually n = >29, but ideally, I like to see at least 500 data and strive for 1,000, or more, where practicable. Those larger numbers are unlikely to be attainable by the average amateur engaged in testing and are even a bit of a stretch for very well-funded gov't laboratories.

In most cases, an n = 10 will weed out most anomalous performance issues in 10% ordnance gelatin testing. I have absolutely ZERO confidence in the ability of the Clear Ballistics stuff due to the numerous issues surrounding its use so I never bother with it. In addition to the problematic material properties of the Clear Ballistics Gel, the manufacturer often (and without warning) alters the formulation of their synthetic gel product further confounding the process of generating meaningful data.

[awp_101]

Insofar as the statement that the Clear Ballistics gel product ''does fine'' for non-expanding bullets, while the Clear Ballistics gel will inaccurately represent the maximum terminal penetration depth of FMJs (assuming that the FMJ remains in stable nose-forward flight for the entirety of its passage through the gel block), it will certainly demonstrate that FMJs and other non-expanding bullets are capable of deep penetration. Where amateur testing is involved, I think that Chuck Haggard's assessment of ''just fine'' is the equivalent of the ''good enough'' found in the quote, ''Perfect is the enemy of good enough'', commonly attributed to Voltaire.

No, sir, Chuck essentially got it right in the video and he clearly demonstrates a grasp of the deficiencies of the Clear Ballistics Gel product.

Check the video starting at 2:16:50.

Here's what Chuck said in his comparison of terminal ballistic performance (expansion, penetration, etc.) of bullets in 10% ordnance gelatin to that observed in Clear Ballistics Gel:

''Then it folds the mushroom against the shank of the bullet a little bit harder so what you end up with is less of an expanded diameter and if you have less of an expanded diameter you're going to get more penetration...''

That pretty much sums it up.

Would it be fair to say that when evaluating a FMJ load at pistol velocities CB can give an estimate of penetration that's "close enough for government work"? Especially if one were to look at the numbers and subtract say, 10-15% to be on the safe side?

[the Schwartz]

Would it be fair to say that when evaluating a FMJ load at pistol velocities CB can give an estimate of penetration that's "close enough for government work"? Especially if one were to look at the numbers and subtract say, 10-15% to be on the safe side?

That's hard to say without a whole grocery bag full of qualifiers.

I suppose that it all depends upon how you might choose to quantify the ''close'' part of the phrase, ''close enough for government work''.

One of the really frustrating properties of the Clear Ballistics Gel is that there is no simple linear conversion value that can be used to convert or ''normalize'' Clear Ballistics Gel data to convert it to its equivalent value in 10% ordnance gelatin—even in the much simpler case of non-deforming projectiles. A simple variance of ± 10% or 15% is really a very broad range because the range is actually double the value of the numerical uncertainty. Making the ''normalization'' process even more complicated is the fact that even within any given class of non-expanding projectiles, (FMJs, wadcutters, etc.), one variation of a specific design may exhibit a strictly positive variance while another variation (weight, diameter, very slight change in nose geometry, etc.) exhibits a weakly negative variance or even no variance at all. So, in some cases where FMJs of a certain caliber and weight might trend toward the higher side of the range than lighter and/or heavier FMJs in the same caliber, how do we manage to make that prediction so that the resulting estimate is ''close enough''?

Then, where expanding projectiles are evaluated, there is the added complexity of the lower dynamic pressure (caused by the significantly lower density of the Clear Ballistics Gel compared to 10% ordnance gelatin) that under-drives projectile expansion and over-represents maximum terminal penetration depth. Since the purpose of the test medium is to drive projectile expansion at the correct rate—which in turn determines maximum penetration depth—how does one determine the correct value for the ''normalizing'' expansion factor that is called for in each case?

In the following tables for two of BrassFetcher's side-by-side comparisons of a single JHP design (Sig's V-Crown)—of differing caliber, mass, and sectional density—fired into both test mediums, the coefficient for ''normalization'' is not fixed and doesn't seem to follow any simple linear progression.



In this example, the coefficients (0.819 for the 9mm 115-grain V-Crown and 0.753 for the .40S&W 180-grain V-Crown) seem to be inversely proportional to the mass and sectional density of the bullet and proportional to the velocity of the bullet. The relationship between the two coefficients is clearly non-linear ruling out a simple numerical ''normalizing'' value (such as multiplying by 10%) as the answer, too.

From what I've seen in terms of how non-expanding bullets behave in the Clear Ballistics Gel material, variances of ±25% are not uncommon. That means that there is a 50% range over the bullet's total penetration depth. In the case where a 9mm 124-grain FMJ @ 1,180fps would penetrate to a depth of 29 inches in 10% ordnance gelatin we could/should expect the same bullet to penetrate to a depth of 36 inches (that's 7 inches farther) in the Clear Ballistics Gel. There's also no guarantee that ±25% will apply to all FMJs regardless of sectional density or diameter.

So, how ''close'' is ''close enough''?

I'll be damned if I know.

[awp_101]

Dammit, math ruins everything!

[the Schwartz]

Dammit, math ruins everything!

Mathematics is a harsh mistress. Whether we agree with them or not, we are constrained by her terms.

[5pins]

I watched that Saturday and was struck by 2 things.
One was that according to Fricke the Border Patrol sets minimum penetration at 8 inches in ordnance gel and only tests auto glass, 4 layer denim and bare gel.The other was Haggard stating that for non expanding bullets the Clear Ballistics gel does fine.
Thoughts on that?

ICE used to conduct testing for CBP, and I think they used an 8 or 9 inch penetration minimum. CBP is now using the 12 inch minimum.

CBP now has a third-party conduct testing for them. Testing consists of bare gel, light clothing, heavy clothing and windshield.