You have to remember that over 140 years ago, there wasn't much emphasis placed on keeping track of weapons & what soldier received such weapon. Serial numbers meant very little to the army & very few companies kept records by serial number of issued weapons & it wasn't until after the debacle at the Little Big Horn 11 years after the war, did the military start keeping track of weapons by serial number. I don't think I have read any where a soldier was responsible for a lost weapon but I suppose it could have happened. It was not uncommon for a soldier to pick up another weapon if his became unusable & nothing more said about it. In the South, most soldiers would replace their weapons with Union weapons found on the battlefield. As far as soldiers leaving their weapons with the unit if they were hospitalized, I have a friend that has a Spencer carbine that was issued to a Union soldier that was hospitalized numerous times & evidently, he kept the weapon with him as he purchased the Spencer from the army when he was discharged after the war (a fairly common practice if the soldier could afford it) & his descendants decided to sell the carbine & my friend bought it. You cannot compare the army in the Civil War to the modern army of today. Even with the tight control of issued weapons today, many still do come up missing, serial number or no serial number.