I think the US Army was the dummy here. There’s definitely an appearance of poured melted explosive filler in the HE compartment of the shell, yet the well for the detonator cup (which is supposed to be empty) was filled with sand or a sand-like substance giving the 81MM shell the appearance of a sand-filled dummy. Indeed, that would have been a clever way of stealing TNT from Picatinny Arsenal (back in 1967 anyway.) Got to add that this thing was stored in an attic that reached 130° in summer and that it really looks like the filler in the HE compartment has behaved like TNT subjected to high heat. It’s an explosive compound in my opinion.

In my view it is very hard to determine a filler only by visual inspection since there is plenty of replacement fillers with similar appearances.

But do they go that far with ‘dummy’ rounds? I mean to use a poured filler, and aren’t they usually marked or color coded? The 40MM grenade in the photo is an example of what I mean… it’s clearly marked “Proof” and color coded black to identify it as being solid. Anyway, I hope it is inert filler. That way I can just toss it in the garbage. I don’t think there’s anyway to remove it. This shell wasn’t part of my dad’s or mom’s collection so I am a bit wary of it.

The markings are on the outside, so why marking the compound?
As the “dummy” is given in hand writing it also could have been a TP and sowith it should have a matching weight (even propper dummies should).
Also we must assume it was repainted at some point as the color of that one does not fit known schemes.

Your 40mm is solid aluminum.

Thanks for your expertise. The cause of my willies may have just surfaced when I remembered that the plastic tube it was in was stenciled “Comp. B.” Of course that wouldn’t have been the original tube (?), but subconsciously I knew the marking. I do prefer handling ones like in photo (ones obviously inert.) I bought it from my mom’s estate so I can pass it on to a collector. Even if I get less than I paid that’s OK, it really does belong in some collection. Can’t be too many of them, and I think you may be right about it being a practice shell. I can’t find any images of a blunt-nose 14", and the images I see appear to show them with a hardened steel nose or sheath on the front. Something else from my dad’s collection you might find it interesting. It’s a war trophy he acquired when he was an Air Tech Intelligence officer in 1945 overseeing the gathering up of German aircraft tech. It’s a 1945 German design model… a Heinkel from the looks of the nose and canopy. It’s real. Thanks again.


I do not know about what you’ve found, but several years ago I bought an M-117 (de-miled) 750 lb. bomb. Upon doing research on them I found multiple sources saying that the way they were de-miled was to melt the HE out with steam. The cavity was then filled with plaster. That is what was in the one I bought.

I DON’T know what I’ve got either… I suppose it’s best to keep it that way. I only know that it melts before it burns, and that on an anvil it is insensitive to hammer blows and forceful friction. After I did the anvil test I used a large auger bit to break it up. It worked so well and without the potential for environmental contamination or toxic dust should it have actually been an explosive or chemical compound. Yes, steam would sound like the proper way, maybe the only way for something that big. I did consider steam after reading your post. Thanks. John