I'd be more inclined to either sks or 9mm
Camp gun, due to cost of ammo, potential for suppressed work with heavy,subsonic bullets, cost of gun (sks, anyway,or I'd step all the way up to a CAR-15. The carbine you speak of is sort of neither fish nor fowl, to me, anyway. If the can is not an issue, then it makes more sense. Maybe the CArbine's rifling is "fast" enough twist to handle a heavier, subsoic bullet? Then the $300, used Marlin Camp carbine, in 9mm, would only have ammo cost and it's lack of much blast (indoors) to recommend it over your carbine. That can be a pretty big issue, for a non-gun type of person, say an elderly one.
Camp gun, due to cost of ammo, potential for suppressed work with heavy,subsonic bullets, cost of gun (sks, anyway,or I'd step all the way up to a CAR-15. The carbine you speak of is sort of neither fish nor fowl, to me, anyway. If the can is not an issue, then it makes more sense. Maybe the CArbine's rifling is "fast" enough twist to handle a heavier, subsoic bullet? Then the $300, used Marlin Camp carbine, in 9mm, would only have ammo cost and it's lack of much blast (indoors) to recommend it over your carbine. That can be a pretty big issue, for a non-gun type of person, say an elderly one.