Despite this, the Fireflies increased firepower was much valued by British and Commonwealth tankers, and during many engagements, the Firefly proved its worth, knocking out the feared Tigers and Panthers at long range, as well as less formidable tanks like the Mark IVs and StuGs.
One example of this increased firepower was displayed by Lt. G.K Henry's Firefly during the defense of Norrey-en-Bessin on 9 June against an attack by the 3rd Company of the 12th SS Panzer Regiment of the 12th SS Panzer Division. Determined to capture the town in preparation for a larger offensive to drive the British and Canadians back into the sea, Kurt Meyer ordered an attack by 12 Panthers of the 3rd Company and infantry to attack Norrey-en-Bessin and drive the Canadians out of the town. The attack got underway at 1300 hours with the Panthers racing to the town at full speed only to stop to fire their guns, quickly outrunning their infantry support. Within 1,000 m of the town, 9 Shermans of the 1st Hussars opened fire into the advancing Panthers flanks. Lt. Henry's gunner, Trooper A. Chapman, waited until the Panthers "lined up like ducks in a row" and quickly knocked out five German Panthers with just 6 rounds. The attack was repulsed with the loss of 7 of the 12 attacking Panthers, the majority credited to Lt. Henry's single Firefly. [7].
Another similar example occurred on 14 June, during Operation Perch, Sgt. Harris of the 4th/7th Dragoon Guards, along with three standard Shermans, set up defensive positions along with the infantry after successfully driving out the Germans in the village of Lingèvres, near Tilly-sur-Seulles. Looking through his binoculars, Sgt. Harris spotted two Panthers advancing from the east. He opened fire at a range of 800 m, knocking out the lead Panther with his first shot, and the second Panther with his second. Relocating to a new position on the other side of the town, he spotted another three Panthers approaching from the west. From his well-concealed flanking position, he and his gunner Trooper Mackillop eliminated all three with just three rounds. Harris and his gunner had knocked out five Panthers with as many rounds, once again demonstrating the potency of the Firefly, especially when firing from a defensive position on advancing enemy tanks.[3]