"How much do you wanna bet the insurgents/terrorists who 'found' this seemingly normal bomb are now looking for more just like it- to use it as intended?"
I have a sneaking suspcion the thugs who set that bomb are going right back to where they got it from. They probably came across a pile of these shells to use for IED's. Now that they know what they have they'll go back to that stockpile and get more.
Now if we could just track these rats back to their hole...we might find a pretty nice little stash of WMD artillery shells.