I would guess that by the flat spot under the serial number, this rifle has been renumbered at one time. As such, the bolt may well be "force-matched", although I don't really like this term. Mind you, the serial on the bolt doesn't look very factory either. Satisfactory shooting can be achieved with a mismatched bolt provided the headspace is brought to specs.

Interesting marks on the rear sight. I don't recall seeing the broad arrow in a diamond before.