Army - 40th Artillery Branch Wo Txt Classic T ShirtSolid colored t shirts are 100% combed ringspun cotton, however, heathered colors could contain a cotton polyester blend Preshrunk to minimize shrinkage The 40th Field Artillery Regiment was first constituted in the National Army as the 40th Field Artillery on 5 July 1918 The 40th participated in eleven Vietnam War campaigns The Regiments last combat action came in the Southwest Asia conflict, aka the First Gulf War.