It’s either a primitive sextant or a disgronificator.
5.56mm
They had the astrolabe or something like it. All these examples were found inland, and occasionally in the grave of a posh woman.
https://www.google.com/search?q=astrolabe&tbm=isch
Oh, for all — the Brave browser has intro’d its own URL-line search engine. It can still be configured to default to other search engines though.
I miss Rush