Battery A 266th field artillery battalion in ww2

My grandfather is listed as being a machine gunner, responsible for the work of 8 men in firing and maintaining a 50 cal machine gun.  He was a corporal in Battery A 266th Field Artillery Battalion.  I would love to know a bit more about what he would’ve experienced. He didn’t talk much about the war other than being too close to a howitzer and that’s why he had trouble hearing.  His separation paper says northern France, Ardennes, Rhineland, Central Europe and Normandy.  I’ve tried to research the actual moments of the 266th but it has hard to find. I know they were called ‘Dandelion’ and I know there was a book on their movements but, other than in two libraries 1000 miles away, I can’t look at it.  If anyone can explain his movements and/or what he did (besides shooting a gun), I would be extremely grateful.