On 21 December, after the start of the German offensive in the Ardennes, the Seventh Army was ordered onto the defensive. A Company of the 824th was attached to the 106th Cavalry Group, covering the far left flank of the Army, while the other two gun companies remained with the infantry of 100th Division. The anticipated enemy offensive, Operation Nordwind, began on the night of New Year's Eve. After heavy infantry fighting, German armored units were engaged on 8–9 January 1945, when the 17th SS Panzergrenadier Division attacked the 397th Infantry Regiment, supported by B Company of the 824th; one gun was lost in return for one tank and several half-tracks. This is the only occurrence noted in the battalion history in which the battalion engaged enemy armor. Two guns were temporarily abandoned by B Company when their supporting infantry retreated. A group of eight men returned to recover them the following night; all were awarded Bronze Stars for bravery. Additionally, one gun commander was awarded the Bronze Star for holding his gun in an exposed position during an attack.