After reading this, I came across this article discussing specifically the German forces 88mm howitzer: http://99div.com/olddirect/american_and_german_field_art

After reading this, I came across this article discussing specifically the German forces 88mm howitzer: http://99div.com/olddirect/american_and_german_field_artillery_in_the_battle_of_the_bulge+cb01biggio+416d65726963616e20616e64204765726d616e206669656c6420617274696c6c65727920696e2074686520426174746c65206f66207468652042756c6765 http://99div.com/olddirect/american_and_german_field_artille... It seems that from that it really wasn't the American's accuracy that enabled their simultaneous fire, but rather the American's understanding how important coordination was with artillery and starting from just after WWI working on making that a reality.