It is my understanding that you have to pay an a additional “rider” policy to cover guns.
Could vary by policy - I work for Allstate claims and there’s no limit on guns, except for theft. Same with jewelry. You can schedule individual “expensive” pieces if you want (which would entail listed them in detail) or add a blanket rider to just increase the base policy. There’s usually a section for “limits on certain property” and that’s where it’d be found.