Speer Gold Dot G2 147 grain PT 9mm

[NotAnExpert]

By definition, a model is a simplified version of a system that intentionally ignores certain details and complexities to focus on key factors of interest. Not all models are created equal, but good models are useful as long as they can consistently and accurately predict results in the real world.

There is a lot of support out there for the adequacy of proper ballistics gel testing, and our resident expert says so as well.

So can someone design a product from the ground up to perform well in, or even ace a given test? I'd say yes. But if this test is a good model for bullet performance in the real world, why wouldn't you aim to ace that test?

[El Cid]

So can someone design a product from the ground up to perform well in, or even ace a given test? I'd say yes. But if this test is a good model for bullet performance in the real world, why wouldn't you aim to ace that test?

Good point, especially since the failure in real world shootings will still mean the product fails and falls into disuse.

[nycnoob]

Properly prepared and calibrated 10% ordnance gel at 4 deg C is not some kind of magical secret; it has been the industry standard now for 30 years for good reason.

Doc, my reading of MacPherson is that even "Swedish Soap" could be used with the correct protocolls:
(for this quote you need to know that "high velocity" is defined as over 600 ft/sec)

"the high velocity penetration model is qualitatively the same in soft solids and low viscosity liquids. This somewhat counter intuitiveresult is not only true for ordnance gelatin but also for soft solids that do not appear at all like tissue (eg soap). This model shows that the only relevant soft solid stimulant parameter at high velocity is density. Most popular stimulants (soap gelatin at any mixture) have densities close to that of tissue and so give good simulation of tissue in high velocity penetrations (but not necessarily at low velocities when viscosity effects are important)." P77 of Bullet Penetration 2nd edition.

It would seem to me that even if it was tested in some nonstandard gell that would expect "similar" results though not exactly something that you would want to publish the data points of.
It would seem that bullet expansion should be robust with respect to the test medium.

[Sparks2112]

Doc, my reading of MacPherson is that even "Swedish Soap" could be used with the correct protocolls:
(for this quote you need to know that "high velocity" is defined as over 600 ft/sec)



It would seem to me that even if it was tested in some nonstandard gell that would expect "similar" results though not exactly something that you would want to publish the data points of.
It would seem that bullet expansion should be robust with respect to the test medium.

The ATK engineer didn't suggest even once that the gel had anything to do with why the bullets didn't expand. His immediate reaction was that there was something wrong with the ammunition I had.

[Sigfan26]

I'm gonna stick with the stuff i got (Doc's list, minus the G2). If it works in clear gel AND ordnance gelatin, I'm not gonna doubt it!

[GRV]

dove--Please review the Wolberg SDPD study comparing autopsy results in OIS incidents with effects in 10% ordnance gelatin.

Properly prepared and calibrated 10% ordnance gel at 4 deg C is not some kind of magical secret; it has been the industry standard now for 30 years for good reason.

Thanks for the reference! I just gave it a read. It looks like bodies are indeed pretty high variance, but the gel does a good job of being a guideline for the average overall performance. I didn't doubt that, because in 30 years, if it wasn't damn good, we wouldn't have stuck with it; the faults would have been exposed.

What I'm getting at is something that Wolberg's scientifically prudent language leaves open:

[...] it is concluded that this gelatin can be a useful predictor of this bullet's penetration and expansion characteristics in shots in the human torso.

(emphasis added)

Ballistics gelatin has worked for 30 years, but the Critical-Duty/G2-style PT is a new innovation, as I understand it, and it seems like a pretty significant deviation from the past 30 years of design, with purposefully different dynamics. Based on my experience in seeing highly trusted models overturned elsewhere in the sciences, it just strikes me as the sort of turning point that might lead to such a paradigm shift.

I'm definitely not looking to ruffle any feathers here, and I personally think it is probably nothing so grand at work here, but rather something much more mundane like a bad batch of rounds. Like I said I'm just tossing thoughts around to pass the time

[NotAnExpert]

Ballistics gelatin has worked for 30 years, but the Critical-Duty/G2-style PT is a new innovation, as I understand it, and it seems like a pretty significant deviation from the past 30 years of design, with purposefully different dynamics. Based on my experience in seeing highly trusted models overturned elsewhere in the sciences, it just strikes me as the sort of turning point that might lead to such a paradigm shift.

This is certainly a possibility, as far as modeling is concerned. I am by no means implying that such rounds can't be modeled by ballistics gel. I have not the data nor the experience to make a judgement one way or the other.

But, by no means should we jump to conclusions based off of the limited, non-scientific testing we have seen on this ammo thus far.

[GRV]

But, by no means should we jump to conclusions based off of the limited, non-scientific testing we have seen on this ammo thus far.

Absolutely agreed. I hope I didn't give the impression that I was concluding anything here. The chain of events just has my brain pondering the possibilities.

[Symmetry]

I'm gonna stick with the stuff i got (Doc's list, minus the G2). If it works in clear gel AND ordnance gelatin, I'm not gonna doubt it!

I might just go ahead and grab a box for testing, but I do agree that I would have MUCH more trust in a modern, traditional HP design like the HST. The only time I want my projectiles to expand is when they encounter a hydraulic media such as tissue, and that projectile should expand under a broad range of tissue densities and water concentrations. It seems that the shallow HP cavity, combined with the polymer filling on the G2 was setup to make the ogive section of the projectile more durable and increase case capacity.....likely to ace the windshield test. At this point I would give the technology some more time to mature(if it has merit), before I trust it with my life.

[El Cid]

The ATK engineer didn't suggest even once that the gel had anything to do with why the bullets didn't expand. His immediate reaction was that there was something wrong with the ammunition I had.

And would that ammunition be in a box like the one on the left? Or the one on the right? Thanks!