Welcome to the site. I have built my own gun cabnit but no plans. Just played it by ear. I like cabnits better than safes, seems this country is in one hell of an uproar over everything anymore. I took a different attitude and taught my kids about guns. Would send you a photo but haven't re-done it yet since my house burned.
Just keep in mind, your building a box to keep your guns in. Take it from there.
One of the things I struggle with when afield is keeping my rifle clean and in good working order. Small amounts of dust and dirt collect moisture; moisture can freeze rendering your action immovable when you need it most. I have seen this happen on multiple occasions, and over time, I’ve learned the cause and how to prevent this from happening.
The first thing that you need to avoid before going afield is leaving excess oil on the gun. Oil will trap dirt and sand in all the wrong places....