By October and November 1943, enthusiasm began to grow for the project. The 21st Army Group was informed of the new tank in October 1943. Even before final testing had taken place in February 1944, an order for 2,100 Sherman tanks armed with 17-pounder guns was placed, as the Challenger programme was suffering constant delays and it was realised that few would be ready for Normandy. Even worse, it was discovered that the Cromwell did not have a turret ring wide enough to take the new High Velocity 75mm gun (50 calibres long), so it would have to be armed with the general purpose Ordnance QF 75 mm. This left the Firefly as the only tank available with firepower superior to the QF 75 mm gun in the British Army's arsenal, earning it the "highest priority" from Winston Churchill.