7,92 Imploded


Found a nice German 7,92x57 that seems to be implode.
Must be an extremely force to get a cartridge like this
even the primer is pulled inside. What would be happened to the powder?



Now that is one interesting cartridge! Never saw anything like it before. I wonder what would cause something like that?


Could it have been recovered from very deep water (say a few thousand feet) somehow? That’s all I can think of that would cause that.


It certainly seems to have been subjected to great external pressure as Falco suggests. Perhaps it was near a large explosion and the overpressure did the damage. After all, very strange things happen close to large explosions.



This is a question, not a explanation. Aircraft machine guns work at very high rates of fire, in short, fairly violent actions. Could this be a jam cleared after landing from one of those guns? I am not familiar enough with foreign machine guns, especially aircraft guns, to know what could happen or what couldn’t. I have seen a couple of really badly damaged and mangled rounds come out of Browning 1919A4s that jammed due to improper headspace setting or introuction of an already bent cartridge into the mechnism.

Up to those who know these guns better than I to decide if this could be a product of a jam. I am just suggesting another avenue of approach. Admittedly, I have not seen this type of damage, except on one side, on a small arms cartridge before, and have no real answer for it myself.

John Moss




I have a belt of three rounds of mangled 7.92 that was recovered from a crashed Me110. It looks a bit like that but the cartridges are suitably scratched and gouged from being in a crashed aircraft.

That round sure looks like the pressure was applied evenly by a medium such as water. Apparently the pressure at the depth of the wreck of the titanic is 6500 PSI, and probably less than that would do that to a cartridge. However, it looks too clean to have been in water for any amount of time. Also, I would have thought that much pressure may have forced the bullet out at least partly, and the bullet appears to be seated normally.

I would have thought it would have also been more scratched if it had been mangled in a gun mechanism.

It is quite likely we will never know.


Very strange. I’m inclined to go with Falcon’s deep water theory but if the pressure was that great wouldn’t the bullet have been pushed back into the case?


Again, I am asking a question because scientifically speaking, I am ignorant in the extreme. If the pressures of the depth of the Titanic wreck would crush a cartridge like this, why, in photos of the wreckage and the area, did we see things like porcelin cups and plates, and in one instance a shoe, on the ocean floor undamaged? Do those pressures work on objects with a very small surface, like they wood, perhaps, on the hull of a submarine or some extremely large object. Deck objects on the Titanic wreck, in the photo documentary I saw, while missing all the wood because of organisims that basically eat it, were in tact, like one of those circular things with a lever that singles the engine room as to what speed to go, etc.

Just wondering.

I wonder if this damage to the cartridge could have simple been done purposefully, like someone squeezing it in a vice or powerful pliers or something. I agree that is unlikely, and also that it is unlikely to have been a jame, after really inspecting the photo and seeing that it is not scratched up.

It is an interesting topic and once again, I am just exploring possibilities “out loud” and not offering an opinion of what happened.

John Moss


John–The pressure would only crush things with an internal void and were not vented to the outside, so things like porcelain and shoes would only shrink a very small amount depending on the pore space of the material. If the bullet had loosened enough to allow the internal pressure to equalize with the water pressure, then it would not have crushed.


I suspect you could get that kind of result from a high pressure test chamber as well as under ocean water pressure. Bill


Ron - Thanks. I understand now, and it makes sense even to an old Liberal Arts Major like me. I took exactly one science course ever - Biology in High School, because I didn’t want to take chemistry and you had to have one year of science to graduate. So, at least I know my elbow from my ankle. Not much else though.

John Moss


This is a typical damage as it occurs when a cartridge was near an expolsion, In particular when it was surrounded by a liquid when it happened (in this case maybe in leaked out oil, fuel, loose ground or the like). It also might have been pure blast without the prior mentioned materials involved, less likely but also possible.
I have seen plenty of such cases/cartridges which have been close to explosions like intended demolition, accidents, combat scenes etc.


I’m somewhat inclined to agree with EOD, but in my mind, in his scenario, the primer would be pushed out, not sucked in. Plus, the case should look more “crushed” instead of imploded. When I went through SCUBA training, we were shown the crushing effects of water pressure on a 1 gallon metal can. At the surface the can was full of air, but at 50-60 feet down, it was crushed like a ball of tin foil.

What I am thinking is that somehow, for some reason, the cartridge case got very hot then was rapidly cooled. The rapid contraction of the air/gas/whatever inside the case caused the implosion, to include sucking the primer deeper into the primer pocket. Extreme heat would have softened the brass enough for it to deform more easily. On the other hand, extreme heat might have set off the primer, and lacking crimps, blown it right out. It appears to me that the usual case mouth crimp is not present, leading me to think the projectile got displaced at some point in the event that caused this. Also noticed the primer lacks any crimping or annulus. Is this normal? Another question that begs to be asked is “where is the powder?”.

The lack of crimps and annulus and odd nature of what happened to the case suggests this came from a testing ground or was from some experiment?



Surely it’s likely that the amount of heat needed to cause this degree of plasticity in a brass case would also have caused the detonation of the primer along with the powder. This amount of heat would probably also have caused oxidisation (or at least discolouration) of the case. The colour appears very even all over, does it give any indication of having been cleaned?

Also, as AKMS says ‘where is the powder’? It might still be inside the case but highly compressed, what does the cartridge weigh? Also, what’s the overall length?

It might be illuminating for those that know their way around this type of cartridge to comment on how it might differ from those usually seen with this headstamp. Is the lack of neck crimp, primer staking or annulus significant?

Maybe it’s just a badly resized case from some over enthusiastic handloader with a very heavy duty press?

Happy collecting, Peter


I think Falcon was on the right track. I have seen similar fluting in the afterburner of a jet engine after a compressor stall caused a negative pressure inside the AB. Brass is pretty ductile and it doesn’t take a lot of depth to generate pressures to do this. My guess is that a rapid drop into 100 feet or so of water would probably do this. The air inside is compressible and would be rapidly forced out through the case neck and around the primer. I’d just about guarentee that liquid caused this compression. An explosive pressure wave in even shallow water could have done the same thing. I expect that if this round was laying in a puddle of water when a bomb went off nearby, maybe not too near, you would see exactly this sort of damage.




[quote=“EOD”]This is a typical damage as it occurs when a cartridge was near an expolsion, In particular when it was surrounded by a liquid when it happened (in this case maybe in leaked out oil, fuel, loose ground or the like). It also might have been pure blast without the prior mentioned materials involved, less likely but also possible.
I have seen plenty of such cases/cartridges which have been close to explosions like intended demolition, accidents, combat scenes etc.[/quote]

Did anyone actually read this?


EOD, I was agreeing with you. Any detonation nearby that generates a significant overpressure blast wave would do it. I was just enjoying rambling on. It comes with my age!!!

The overpressure that fluted the afterburners probably wasn’t that great cause they had a big hole in the back.




Interesting treat.
To my opinion the case is not cleaned after a closed examination I spot a very small
haircrack in the middle of the case. Around the crack you see a light discoloration.
The case seems empty, weight is 372 grain.
There was never any neck crimp and you can`t see any color around the primer.
Could it be a factory experiment because there is no neck and primer crimp?
Wen it have caused under water by ( let say a depthbom) how came the cartridge back on land.



You often see “trench art” cases with the same type of feature. Usually they are bigger caliber such as 37mm. How were those trench art cases made???

forums.gunboards.com/showthread. … trench-art