On 8 August, advancing to Beaucort, "A" Squadron captured a complete German Brigade HQ, complete with all the staff, maps and papers.
On the 10th, the Garrys had to advance up the Roye Road toward Hill 100. The fields were blocked by trenches and wire, so three troops of "C" Squadron galloped straight up the road through clouds of dust. Machine gun and shell fire left the road strewn with the bodies of horses and men. The last rider fell 100 yards from the objective.
The regiment was not in action again until 9 October, when the advance was slowed by a strong enemy position in Gattigny Wood. Lt. Dunwoody, with 3 Troop, B Squadron, charged the machine guns on the right flank of the wood and succeeded in driving the enemy back. Meanwhile, A Squadron under Maj Middlemast, rode around the left of the wood and charged, killing a great number of enemy with the sword, and capturing 200 prisoners. Shortly after, the remainder of B Squadron rode forward and captured Maurois. The enemy fell back to Reumont, and C Squadron, under Maj Mills, swung north around the village, charged, and captured 42 prisoners and 6 machine guns. With the assistance of B Squadron, the machine gun section, and the Royal Canadian Horse Artillery, the town was secured.
The next objective was the town and high ground near Le Cateau. B Squadron patrols entered the outskirts of the town at night and the position was finally taken by the Royal Canadian Dragoons. The CCB was relieved in place by the 7th Cavalry Brigade. The charge at Gattigny Wood was described by the Commander of the British Cavalry Corps, as "the best cavalry action carried out by any cavalry unit on any front during the war." For this action, Lt. Dunwoody and Maj Middlemast received the Distinguished Service Order, two other officers received the Military Cross, five Distinguished Conduct Medals and eleven Military Medals were awarded.