Mk4 Mod 0

Hello I apologize but I am a new collector and I came across this MK 4 at an estate sale. I would love to know what era it may have came from. The gentleman was a scallop fisherman and said he had pulled it from the ocean while fishing. Any if would be greatly appreciated. Its about 4 or 5 inches wide and about 27 inches tall.

Appears to be a storage or fuze hole cover on a artillery shell of some kind.
But that is a WAG on my part.

Oh well, this is a US navy 5-inch projectile.
When condition is untouched this item may be highly dangerous as it is not only a potential high explosive projectile but also can be fuzed (underneath that top cap you see).
In this case it is a dud and even more dangerous!

In case you are no expert (I assume) call in your local law enforcement and do not touch the item any more.

As per your images you are in imminent danger!


I probably should have mentioned that the shell is empty. I just set the top on it to get the height.

Good !

Then it still remains a US 5inch high explosive (empty) or a target practice projectile for naval guns.

Thank You. Would you have any idea what era it may have come from?

I am no expert in US navy ammo. When there is no clearly legible date in one of the markings it gets difficult.
Maybe the other guys who are specialized in this kind of ordnance can chime in and specify.

The type you have there could be still in service today but also may be from WW2 days:

I’d be interested to see a photo of the shell without the fuse cap on it.

We all can tell Alex has a lot of experience with these types of unexploded ordinance. I know they STILL find unexploded ordinance all over Europe from WW2. Every year an estimated 2000 tons are found in Germany alone… scary, and to think about the millions of tons used during that war is insane.

These are my two, 5"/38 Cal US Navy projectiles. I was told that they are WW2 era. Maybe of interest in case you would like to see the stenciling?



Thanks for posting the pictures. I wasn’t aware that HE shell design was comprised of multiple components.

Does anyone have a drawing of this particular shell?

The “Mark 4 Mod 0” marking only is the designation for the fuze protector cap. It is a pressed steel design. The more common cast bronze cap can be seen in the photos to the left of the blue projectile.
The OD “Common” projectile in APFSDS photos is more of an armor piercing design than a high explosive design, with an extremely thick short body, usually with a hollow core which could be loaded with explosive and fitted with a base fuze. The front of the stubby projectile is fitted with a ballistic cap to make it more streamlined for better ballistics.
The typical high explosive projectile had much thinner walls and a lot more explosive, and usually fitted with a nose fuze, either impact or time.

It would really help to see what is under the cap on your projectile, and also the base to see if there is a fuze there. Without any traces of the paint, it is hard to know if it is filled with high explosive or not. It is also possible that it is like the blue projectile which was used for target practice. These “blind loaded” shells are filled with an inert substance instead of high explosive (e.g.- plaster instead of TNT) and fitted with an inert metal plug like in the blue one, instead of a functional fuze. These are known as “blind loaded and plugged” of BL&P which you can see stenciled on the side.
Some of the BL&P projectiles were made using shells taking only a nose fuze, and some were made for either/both a nose and base fuze.

Knowing what is on the nose and base of your shell will help with determining if it is potentially dangerous.

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Thanks for the correction John. I based my guess on the colour scheme used. It is coincidental that this topic appeared when it did, as I have been offered a case and a fuse protector cap for one of these, in return for printing up a shell.

I should be asking for the drawing of the HE shell but I would still love to see a drawing for the shell shown by APFSDS, as that is interesting and something I would like to have a try at modelling for printing.

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Check out this link for some info on the shell you are curious about:


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Thanks for all of the comments!! Here are a few more20200213_125401_resized 20200213_125410_resized 20200213_125416_resized 20200213_125640_resized pictures.

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20200213_130444_resized 20200213_130606_resized

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Is that remnants of blue paint on the base?
Then it appears to be a practice projectile.

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