I also read the AR article on the Darne the Lt Col brought back. Nothing indicated it was actually used by the Viet Cong as I recall. It was selected from a piled up heap of all types of guns in a warehouse, probably many of which were confiscated civilian guns, which this Darne likely was.
I do not now recall the reason now but this LT Coll was allowed under proper authority to select One (1) gun as a personal souvenir to bring back to the states with authorization. He picked the Darne, an R10 as I recall.
At no place is it mentioned that this is a Lt. Col-in fact, in the line with his name it states his rank as Col.
The first paragraph states, unequivocally, that the gun "was carried through the jungles and deltas of Vietnam, and not on our side".
I have no reason to doubt that assessment, from the Colonel. He was there.
The second picture on the lead page of the article shows clearly a Darne R action, with a sliding breech that is engraved. This level of engraving would not be applied to an R10. The last picture in the article shows what appears to be the entire gun having been blued. At no point in the article is grade of the gun stated.
But, it is not an R10.
Best,
Ted