Almost certainly Spanish - flat bolt bottom for the 1st double stack mag of the 1893, mostly scrubbed receiver ring w/ a faint crest. Looks like the gas escape hole was added, C&Rsenal vids or research will tell you when that was done, which may rule out a Spanish-American war capture. If a US capture gun, then not updated w/ the later spitzer sight, so sights will be off w/ modern spitzer ammo, but the action can handle it. The Spanish ultimately rechambered these guns to 7.62x51mm NATO.
With the flat bottom bolt, a good candidate to convert to 7.62x39mm & AK mags.
ETA: I thnk the R is the updated sights for the spitzer bullet, and if M1916, then not Spanish/American war. Not antique, but no concern about soft bolt lugs from the worry wort in the other thread. Strong action, just doesn't handle gas as well as a 98.