Gerald,
I would certainly accept your explanation concerning this thread & your expertise by your title is much more than mine. Your suggestion to explore the National Archives to glean such information is one of the many but time consuming ways to find such information. That is why Springfield Research Service provided such a wealth of information concerning weapons issued, serial numbers, etc. as the founder of the service spent countless years & hours going over records at the archives. His initial charge to provide records if you found your serial number among the thousands of numbers he had compiled, was worth the money. Unfortunately, those who wanted to make a fast buck, misused the service & the now owner of the service, pulled it from the INTERNET.
As it may have been "by the book" for an ordnance Sargent to collect weapons from soldiers who fell by the wayside, there are many exceptions to this. I do know by letters, the individual who carried the Remington revolver that I have & by witnesses to his application for disability pay, stated that he had collected his belongings & weapons when he left the hospital. One instance when his company was on patrol to Springfield, MO. & while en route, he became ill & was hospitalized at Warsaw,MO. While in the hospital, he missed his comrades (I would assume it was more the primitive care & unpleasantness of the 1860's hospitals), he gathered his blanket & weapons, & walked back to where his company was camped. There would be many instances where it was impossible for an ordnance Sargent to be present to collect weapons plus, no way to store such weapons if all were traveling with bare necessities & only have the horses each soldier was riding. With a cavalryman, you not only had to collect his sidearm but also his carbine & saber. Thats a lot of iron to transport if you had very many troopers requiring hospitalization.
The status of an infantryman possibly might be different but that is for another post.