All good points and I would add that the logistical problems of the additional ammunition required to realize the potential of repeating arms would not have been overcome during the war. Without proper training, it is imaginable to have soldiers fire all the ammunition in their packs quickly and then be out of service for the rest of a battle.I should perhaps make something clear, perhaps for the first time if I haven't stated it properly yet.
The argument has never been that repeaters are a downgrade or even a sidegrade compared to the weapons used by the Union army in the Civil War.
The argument is:
- Repeaters have disadvantages as well as advantages.
- There is no feasible way to get enough repeaters to equip the Union Army (or even one army thereof; you could probably equip a corps but that's about it) even by the end of the war.
- If you compare a repeater to a rifle musket used by someone properly trained in how to use it, then which weapon is superior depends on the engagement range.
- If you wanted to upgrade the Union Army's fighting capabilities enormously, it would be cheaper and much more possible to train them to properly use the weapons they already had.
Of course, if you were able to both rifle train the army and equip them all with repeaters, it would be better than doing either by itself (at least at defeating the Confederate army).