Your guns are much like the accumulation I have-worth more to me, for various reasons, than they would be on the open market. It is doubtful that professional gun thieves will target us. What we are primarily up against are punks, that seize the opportunity we leave them to jack our stuff.
I've seen the small, sheet metal locking gun cabinets that are sold by discounters, but, would only consider them for the storage of ammunition, or as a decoy. A cordless die grinder with two or three fresh lithium batteries will make quick work of them. A punk only needs to create a hole big enough to get your stuff out. Chuck is correct, a safe needs to have some mass, and to be secured to a floor.
I have seen some great deals for used safes on the local Craig's List, usually people who are relocating and want to sell rather than move a safe. I bought my safe 20 years ago, it is a smaller Liberty safe, but it weighs most of 600 lbs and holds about what you are looking for, depending on which interior is installed ( I bought two different configurations of interior for it at the time).
I didn't buy fire protection for my safe. A friend was on the local fire department and assured me he had never seen a safe come out alive after a good, ripping, house fire. Others, feel differently. A safe really just buys you time in the event of a robbery or a fire. If either calamity has lots of time, you will probably lose your guns.
What ever you do, it is wise to buy the safe before you suffer the robbery. You wouldn't believe the number of people who wait until everything is gone, and then buy a safe.
Best,
Ted
