I thought I remembered reading that at some point in the American Civil War, I thought towards the end, a practical repeating rifle was available for mass production and distribution, but that the department of war shot it down, thinking that they were too complex for soldiers. I also thought that the Gatling gun was available during the war. Are either of these things true? If so, why were what seems to be massive improvements in weaponry refused in favor of older, ineffective weapons?