I did try a forum search for this as a subject, but found nothing.

At the range yesterday I found a handful of shiny silver shells that were obviously 9mm. But -
First, there is a groove around it just forward of the extractor groove. It is machined into the shell and is not nearly as deep as the extractor groove. Looking inside it cannot be seen. It appears to be at the bottom of the powder section.
Second, the headstamp is nearly worn off of all of them. Very hard to see. With a magnifying glass I see, as read from the outside, "9MM LUGER ES".
They are not magnetic.
Pix attached.
9mm case side 25.jpg

9mm headstamp 25.jpg

I can't for the life of me find a way to post bigger pics.

Down below the window that you type a reply message in there is a box called "Go Advanced"

If you click on it there will be some new selections just below it where you can "Manage Attachments"

Click on it and you will be guided into uploading your picture.

Just remember to upload your fullsize/original picture and not a thumbnail

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"Acta non verba"

Your best source of information would be to post the question on the International Ammunition Association (IAA) website forum. No membership is required to access it. The real ammo experts are to be found there. I checked the IAA headstamp list, no ES is shown.

It appears to be a case from Shell Shock Technologies.

Shell Shock Technologies NAS3 Shell Cases, 2-Pc Nickel Alloy ~ Review

1,500 Unprimed 9mm Cases | Shell Shock Technologies

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PC945, TRR8 327, 686PP, Model 14, 342PD, M&P9

If I read all the above correctly, this case modification is simply to make a lighter weight round?

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Possum—The other white meat!

Iffen it ain't broke........Don't fix it.

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S&W Accumulator

I tried to upload pix as small as 500 mp and was refused. Not until I shrank them to pinhead size would they upload.

What do some of the good folks say on here— “a solution in search of a problem.”

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Possum—The other white meat!

My quick read indicates that, in addition to the weight difference, these cases are much more uniform (dimensions, weight), capable of handling extremely high pressures (compared to brass), offer increased corrosion protection, higher lubricity (which could facilitate ease of feeding). Rather than a "case modification" I think this product is more of a change in basic manufacturing processes. The reviewer seems to have been in general agreement with manufacturer's claims.

At a price point of 10 cents per case (in bulk purchase) I might be tempted to try some of these. In my case it would be more an exercise in curiosity than my amateur attempt to create a superior ammo product, but I find it interesting.

I looked at the link Team7 gave, and that is certainly the cases I found.
Thanks to all who replied. Quick solution to a mystery!

Don't forget to buy their proprietary dies in order to load them.

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Still Running Against the Wind

Interesting idea, but I agree with some of the previous posters. A solution in search of a problem. Why go to all the extra effort with a proprietary die with something as common and inexpensive as 9mm. As for higher pressures, whats the point in a 9mm?

I don't think there is a 9mm Luger platform right now that is limited by the ultimate pressure limits of the cases its using. Could be interesting in some of the really hot rod revolver cartridges though with fully supported chambers. I think the 460 S&W Magnum maxes out at 65,000 PSI which is the supposed upper limit for brass cases (I think, I'd have to double check).

I was going to say the same thing many already have...seems goofy to me. 9mm luger brass is just fine, super cheap, doesn't require proprietary dies, cycle/feed just fine and handle any pressure a 9mm pistol is designed to take.

They have bee trying to get their new creation of the ground for over 3 years. I think it was even mentioned before that it flopped and then they tried again.
Advantages? Light weight? Who cares
More reloading? My brass has more reloads then their claim of 7


Light weight bullets? Why again?


Only good thing is you pick them up with a magnet.(whoopee)


There are several old threads on these

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Still Running Against the Wind