I've seen it said from several sources that during the American Civil War some soldiers were able to save up their pay in order to privately purchase repeating rifles to use instead of their standard issue muzzle-loaders. My main question is if they were also expected to supply their own ammunition for these weapons? Or if the Ordinance Department simply had to keep track of which formations contained repeater users and supply them with ammunition for the various rifles?
Some state militias did equip themselves with different guns ,and some ammunition for some of them certainly was supplied by the War Dept.. The Ordnance Dept. was reluctant to buy Henry rifles, complaining that they were not as durable as needed , and so only 1,731 were recorded as having been purchased during the war. But the Ordnance Dept. also bought over 4 million Henry cartridges, so the logical inference is that most of it went to those state militias that equipped themselves with Henry rifles But how many other kinds of guns other than the Henry rifles were supplied is hard to say. The government itself had to buy a lot of guns from private manufacturers and imported quite a few as well. There were a very large variety of breech-loading carbines supplied to cavalry units ( where muzzle-loaders were the least practical), and the Ordnance Dept. did lament the difficulty of trying to keep track of what kinds of ammunition was needed for those. You suspect that there would have been a lot of eye-rolling over constant requests for obscure ammo. For example, they imported 2,000 French Lefacheaux revolvers and 50 cartridges for each one, which doesn't seem that much. But there almost certainly was no one in the US making pin-fire ammunition, and so the Ordnance Dept would have had to actually import more, probably muttering curses....