These are the markings on a US Rifle 1917- on top of the chamber- but the scope is covering that area on yours-
The rifles were produced by Remington at their Ilion and Eddystone plants, and by Winchester at their New Haven CT plant.
What we have here is... failure- to communicate.
Thank you everyone for your helpful posts. I plan to pull the scope off to verify the markings on my rifle and then have local gunsmith verify the chambering.