That thought to be, FA made example looks from the drawing as if a .45 Morse reloadable head might have been used.
Not to say by the arsenal, just that it night have been used.
I would offer the thought, that when these were being drawn, they were included because they existed, not that they were factory or arsenal “pure” product. I have discussed this ‘problem’ with others who, how shall I say this, overlap? the early collectors, who if it was different kept it & maybe, or maybe not, figured out down the road it was good. Or the collectors of today who with the advantage of time, GOOD BOOKS & the internet, have an easier time of distinguishing the differences.
Also note only one of the E. Remington & Sons style raised headstamps is shown.