I could not resist getting this unusual 30MM round. I know absolutely nothing about it but am guessing it is British. The only reason I guess this is the fact the case is marked almost exactly like a 30MM British Reardon (?) case for a Armored Fighting Vehicle. Other then that, I have no clue. Their is a very heavy, dense, thick plastic windscreen that is threaded to screw into a aluminum part of the projectile. I first thought it may be a sabot projectile but it may not be? The main part of the projectile is a one piece, heavy steel sabot thing that surrounds the dart sub-projectile. The only part of the projectile that looks pre-fragmented for separation is the aluminum ring part that the windscreen screws into. Anyone have any clues?