Anyone up for trying to figure out these shrapnel pieces my dad had in his trunk along with his other WWII memorabilia? He was in the 980th Field Artillery Battalion equipped with 155mm Long Toms. These shrapnel pieces show bands and some of the color coding. You have to be careful handling them because these bad boys are really sharp edged.
I have some of those - 1980s vintage though. The big pieces would be very lethal and could travel a long way - hence a peacetime minimum 1000m safety distance for exposed observers. However, big pieces demonstrate an inefficient splinter pattern. Ideally the shell should break up into lots of small pieces making sure that everyone in a smaller area gets a piece.
The ideal piece of shrapnel (actually not "shrapnel" but shell splinters) is about as big around as a dime or nickel. All shell splinters are horrible aerodynamically and lose their initial high velocity quickly. Therefore, the piece should have enough mass to travel a decent distance but not so big as to leave big gaps between them-as Sheldrake mentioned. When I was in the artillery we used the 8" howitzer and that threw pieces up to 400 meters away. Just as an aside, most people don't realize that most shells fired at low angle (0 to 45 degrees) lose half their shell fragments into the ground or up into the air. This is because these shells, in the micro-second between impact and the explosion, slide into a horizontal position on the ground. Thus, only about half the splinters have the potential to do damage. Another aside: In the old history channel forum one poster stated that US shells broke up into (+/-) 30% more fragments then German shells due to superior metallurgy. Does anyone have a confirmation of that?
I recall the 980th FA Btln history frequently mentioned a rain of fragments, or "shrapnel", every time a nearby friendly AA artillery battery opened fire. I imagine he could have brought home buckets of these. The tiny groves on the top fragment look like the rough tool marks from a turning process. If these did not effect the the function there was no need to remove them, and, if they were on the exterior of the projectile, they may have helped with handling by enhancing the cannoneers grip. There appear to be large groves on the left of both fragments. These may have held bands that made contact with the barrel rifling. Though Shrapnel type rounds were made obsolete by high explosive and time-fire, the term was commonly used by the GI's, even those who knew better, perhaps because they knew civilians did not know the difference.