One of the problems the armies had in the Civil War was troops all bringing individually owned weapons to fight with. How do you keep an army supplied when you can never be quite sure what ammo you might need and what modifications had been made to the weapons. In the modern military having everyone fiddle with their own equipment, fixing it the "military way,"(those who have been there know what I mean) causes a whole mish mash of weapons and equipment. Not exactly a prescription for an effective military unit.