Tanks. Being tanks. - (Im reposting this because I found a better photo) The M829 is an American Armor-Piercing Fin-Stabilized Discarding Sabot tank round designed specifically for the M256 120mm L/44 smoothbore
General Dynamics to supply U.S. Army with 120mm tank training ammunition | April 2020 News Defense Global Security army industry | Defense Security global news industry army 2020 | Archive News year