These projectiles are everywhere in the US, I am trying to figure out why. The typical answer would be post-war testing and evaluation, but which war? And why so widespread? Normally a round this heavy might be found regionally (shipping costs), but these are everywhere. I don't remember seeing anything on a large number of the guns across the US.
I've had seven of the rounds, I'm currently down to three but have just been told I'm getting another donated, possibly today. I'm writing a short article for a trade journal, it would be nice to have more info on the background. What other States have we got them in? Owners, not rumors. I've seen plenty of them firsthand in Michigan, Indiana, Ohio and Oklahoma.
A couple years late to the party - I have one of these rounds as well, found in a scrapyard in Richmond, VA. The Haube tip was pushed in to the cavity, so it was easy to see the round was inert. No idea where it came from, but it sits in my office today.