This was in a baggie full of 3-ringers I got at the auction. I bought the bag to get a specific 3-ringer that I wanted out of Dean's collection. The rest of the bag was just extra and this odd-ball was in there. It's a fat bullet .585 to .591 and has the weird cross in the cavity. Non-dug. Has anyone seem anything like it before? Is it from a modern skirmisher?