 In 1862, Dyer was approached by his superiors concerning the possibility of his supplanting General Ripley as Chief of Ordnance, but he declined to take the assignment because he had great respect for his chief, and because he was in the middle of a major upgrading of weapons production at Springfield Armory.On the retirement of General Ramsey, the previous Chief of Ordnance, on September 12, 1864, he was advanced three ranks and appointed as the 7th Chief of Ordnance of the United States Army with the rank of Brigadier General.On December 12, 1864, President Lincoln submitted his nomination to brevet Major General to the U.S. Senate, which confirmed the appointment on February 23, 1865.