From Jan on Patreon:
"What often baffles me is the transition period of various stages of development of gun technology - in particular around the Civil War. What were the types of guns used during civil war and why weren't more modern mechanisms used, if they were available? Was it similar in wars that took place at the same time, but in other areas of world?"

The US Army was well equipped at the start of the Civil War with a pretty good, modern design: the Model 1855 rifle-musket. It was a percussion-fired gun with a rifled barrel and a Maynard tape-primer system. However, the supply of these guns was only sufficient for the basic standing army, and the guns in reserve were largely smoothbores. With huge numbers of new recruits and volunteers to arm for the Civil War, both sides had to scramble to scrounge any and all weapons they could, both domestic and bought form Europe. It took time to get new manufacturing scaled up (and in the South, this was basically never achieved). As a result, the Ordnance Department under Brigadier General Ripley focused on known, proven designs that could be efficiently manufactured in large quantity. He felt - and in retrospect I believe he was correct - that trying to develop new wonder weapons like the Henry would be a misdirection of resources.