 In March 1946 the first prototype could be tested, still with 60 mm armour.The "Atelier et Chantiers de la Loire" built the ACL1 turret used for the prototype, fitted with the American 76 mm gun; this was later replaced by a Schneider turret based on the one designed for the Char F1 and fitted with the 90 mm DCA naval AA-gun which had a muzzle velocity of 1000 m/s (AP; 1130 m/s HE) and a muzzle brake — the ARL 44 was thus the first French tank to feature this item.Firing trials began on 27 June 1947; the gun often proved to be more accurate than that of a Panther used for comparison.