Temporary Cavitation Wounding. Rifle vs. Pistol?

[DpdG]

As for the video, yes it seems they used both clear and real gel, but had the clear block out front. The 13-14in in clear gel seems to be pretty representative of actual performance in real gel (it is my understanding that if anything in clear you will get a little less penetration on average), but like I said more testing needed. I just wanted to be sure he knew that from preliminary results it doesn't look like underpenetration is going to be an issue with the 9x25 77gr load.

“Looking first at the bare gelatin results, on average, the sampled bullets penetrated 35.5% deeper into the clear synthetic product than they did in the organic, 10% calibrated gelatin, with a range between 34.4% (the 135+P Hornady Critical Duty) and 36.3% (the standard pressure, 124 grain Federal HST).”

Source:
https://www.policeone.com/police-pro...kEYB93TAd5o6J/

[Doc_Glock]

Shotgun slugs and large caliber deforming rifle projectiles (think old school 1800's era calibers) can have velocities below 1500 fps, yet offer quite impressive TC effects.

Attachment 34845

Does the temporary cavity of the .45-70 contribute significantly to incapacitation or is is simply a very large and long drill hole?

[StanBan87]

Very interesting test Dpdg, thanks for sharing. I'm honestly a little shocked, I've always heard the reverse and at least in my lay observations of side by side testing the penetration seems pretty similar between gels, just outside of margin of error usually from what I've seen. But this is why I come here.

Seems like the thing to do is to get the 77gr 9x25 loads tested in real gel as I was already hoping to do. I will try to cook some up in the next few months. I hope others who are interested in this potentially pretty exciting project do likewise, the more data the better.

[whomever]

"At least in the case of the 9x25 Dillon with the 77gr SCHP @ ~2100fps, I see no reason why it wouldn't be wounding about the same as that 75gr Gold Dot from a Mk18 or similar at around 50y. "

At the 'assume a spherical cow' level of analysis, which is the boundary of my knowledge, the 77 gr .223 and 77 gr .355 will have very different sectional densities, which is going to affect how/how deep they dump kinetic energy, whether they yaw, yadda, yadda, ...

[Jim Watson]

It sticks in my head that some years ago the Swedish fish and game people did a study.
They concluded that the "pulsatile cavern" became a significant wounding factor at 2650 fps. About what a 140 gr Swedish Mauser is doing, what a coincidence.

[the Schwartz]

@the Schwartz Did you watch the testing video? The 9mm loads using both the 80gr Barnes and 77gr SCHP fail to get much past 10in as you would expect (around 1600fps I believe). But the 9x25 Dillon has a MV of around 2100fps with both bullets, and both go about 13-14in in the blocks. Hardly a definitive test, but they certainly seem to be reaching good levels of penetration with the 9x25 Dillion which is the only interesting part of this really as that is the only one going fast enough to cause serious TCW as far as I can tell.

Yes, I did and I want my three minutes and forty-one seconds back.

I'd agree the testing done the video was 'hardly definitive" as it was conducted in Clear Ballistic Gel product which is notable if only for the fact that it fails to represent correctly the terminal expansion, maximum terminal penetration depth, and temporary/permanent cavities of projectiles being testing in it. As a general and well-documented rule, projectiles that are tested in the Clear Ballistic Gel product exhibit less expansion and correspondingly greater penetration depth than that observed in identical testing in properly prepared 10% ordnance gelatin. Often, and quite unpredictably, projectiles also demonstrate the tendency to rebound from their maximum penetration depth by as much as 40% due to the longer duration of the temporary cavity in the Clear Ballistic Gel product. This occurs because the Clear Ballistic Gel product has significantly lower strain-energy storage and loss moduli than does properly prepared 10% ordnance gelatin. For all of these reasons (not to mention that the manufacturer frequently alters the composition, density and tensile strength of their product and that the product's physical-material properties change over time with each remelt/recast cycle), I dismiss out of hand all testing done in the Clear Ballistic Gel product as inaccurate and irrelevant.

As for the video, yes it seems they used both clear and real gel, but had the clear block out front. The 13-14in in clear gel seems to be pretty representative of actual performance in real gel (it is my understanding that if anything in clear you will get a little less penetration on average), but like I said more testing needed.

No testing in the video that you linked to used validated 10% ordnance gelatin. More to the point above (which I made about the Clear Ballistic Gel product's physical-material properties change over time with each remelt/recast cycle) is that the ''backer'' block in the video is actually a heavily recycled block of the Clear Ballistic Gel product that has darkened with contaminants and residue from prior tests as well as being physically altered by the repeated remelting process. This is one of the other issues that plagues the technology (such as it is) and contributes to the wholesale inaccuracy and irrelevance of the Clear Ballistic Gel product in terminal ballistic testing.

If you are going to conduct any testing, I would encourage you to pursue it through the use of a valid tissue simulant. 10% ordnance gelatin and H₂O are the only two mediums at present that are actually suitable for testing. If you are comfortable with the mathematics required to do so, testing in water (H₂O) requires the use of a modified Poncelet penetration to predict penetration depth as it would have occurred in 10% ordnance gelatin. Books detailing such predictive models can be found here:

https://www.amazon.com/Bullet-Penetr.../dp/B00L7CSV7E

and here:

http://quantitativeammunitionselection.com/

Of course, there is also "going directly to the horse's mouth" and testing in validated 10% ordnance gelatin. There are P-F members here (@Tokarev) who do so with really professional results; I'd encourage you to look up some Tokarev's work. Of course, using correctly prepared ordnance gelatin also has in its favor the added allure of not requiring the predictive mathematical models mentioned just a moment ago if math is not your thing.

[StanBan87]

Definitely sounds like 10% gel testing needs to be done before anything close to definitive can be said. As I said I will be attempting to do so in a few months and I encourage others to do so in the meantime if they can.

[DocGKR]

Hmmmm......drive an all copper bullet beyond it's design velocity and the expanded "petals" fold back or break off, decreasing permanent cavity size and potentially increasing penetration depth.

[Lester Polfus]

As someone who was into 10mm Auto before it sold out and went mainstream, I can tell you that this is not our first rodeo with its bastard stepchild, the 9x25mm Dillon and super light bullets somehow turning it into a hand rifle. We went through this fifteen or so years ago.

It's a really great cartridge if you want to make 9mm bullets blow up and fragment, including monolithic 9mm bullets. There's a world of difference between a 77 grain .223 bullet and a 77 grain .356 bullet.

I've always wondered if someone could get a custom barrel that would allow a person to load the cartridge with .357 revolver bullets. In my thought experiment it seemed like they would feed pretty will as they are being shoved into a 10mm sized chamber. I've toyed with the idea over the years, but wound up just buying a GP100 instead.

Sometimes I go looking for ballistics tests on things that aren't "service caliber" rounds, stuff like .357 loads and etc, and get all excited, then I see it's being done in Clear Gel and I get my sad face.

[Longranger]

As someone who was into 10mm Auto before it sold out and went mainstream, I can tell you that this is not our first rodeo with its bastard stepchild, the 9x25mm Dillon and super light bullets somehow turning it into a hand rifle. We went through this fifteen or so years ago.

It's a really great cartridge if you want to make 9mm bullets blow up and fragment, including monolithic 9mm bullets. There's a world of difference between a 77 grain .223 bullet and a 77 grain .356 bullet.

I've always wondered if someone could get a custom barrel that would allow a person to load the cartridge with .357 revolver bullets. In my thought experiment it seemed like they would feed pretty will as they are being shoved into a 10mm sized chamber. I've toyed with the idea over the years, but wound up just buying a GP100 instead.

Sometimes I go looking for ballistics tests on things that aren't "service caliber" rounds, stuff like .357 loads and etc, and get all excited, then I see it's being done in Clear Gel and I get my sad face.

As the op said, the 77gr Barnes does NOT blow up and fragment at 9x25 dillon speeds. Saying there's a world of difference between two bullets that are the same weight traveling at the same speed doesn't make much sense, especially when you don't say anything to back up that claim.