Forgotten Weapons did a video, not too long ago, on why advanced weapons like the Henry repeating rifle weren’t adopted by the Civil War U.S. Army. Just like today, in time of conflict a lot of people try to get military contracts. Just like today, a lot of those people have poor, unworkable, or under-developed ideas. The rifle-musket with the Minie bullet was very effective. The thinking was “We have something right now that works, is reliable, and we can already mass-produce; switching to something that maybe doesn’t work, we have no idea of reliability, and no way to produce at useful scale is a bad idea — oh, and we don’t have hindsight to tell us which to pick.” The CSA, by contrast, had little choice but to pay anyone who looked like they could deliver arms. Aside from Griswold & Gunnison, it resulted in many failed contracts and few, generally poor-quality weapons.

If you want to binge a great documentary, Ken Burns' The Civil War is phenomenal.