Of all of tank fired DS rounds I have in my collection, I find the design of the 105mm XM797 to be one of the most unique. I decided to deconstruct this projectile to study it better and to eventually make a full up sectioned inert round. Designed as a target practice round it was necessary to limit its over all travel distance so it could be contained on most firing ranges. Unlike most other tank fired target practice rounds that were typically designed with cone stabilizers to limit overall travel distance, the XM797 went a wildly different way. It incorporated a specialized windshield, I think made out of a zinc alloy, that is designed to purposely fail at a certain known distance due to aerodynamic heating. When this happens, the dart body splits in half down its longitudinal axis along a pre-fragmented center line. I do not believe that the XM797 was ever adopted and I have never seen any of its design features incorporated into other projectiles.
Jason
Jason