Are guns safe in a safe? As noted, safes are only delay devices and do not offer any sort of actual long term protection. Sometime back on TFL, I believe, an officer worked a case of a large safe installed in a basement had been taken. The basement was poured, the safe lowered in, bolted down, and the house then built over it. The safe could not leave the house without changes to the structure of the building. The family went on a 2 week vacation and returned to find their home heavily torn up. Burglars had apparently used chains and trucks and ripped the safe from the foundation, up and out the walls of the house. The safe was then carted away for opening at their convenience.
Probably the best way for something to be safe from thieves is to have that something be unknown to start with and then kept in a place where it is not likely to be found. During the Depression, due to a lack of trust of banks, some people turned to "post hole safes" which were things like Mason jars full of money that were deposited under specific post holes. Sometimes these were buried elsewhere, but the name comes from using the fence as a guide. Say you have 2000 fence posts and even if somebody knew you buried money under one of them, it would be a lot of work to dig up all the posts unnoticed.
What most safe dealers won't tell you is that if you have a burglary and the folks find your safe, whether or not they get it open on that trip or steal it on that trip, the knowledge will then be public to them and their buddies. Not only that, but as a burglar who finds a safe, where do you think all the valuables are going to be? Duh! All the valuables are in the safe, right? The safe then becomes a central focus of interest because it will represent a concentrated amount of wealth.
John, neat post on insurance. That seems to be safe advice. Unfortunately the sad part of such events is that while there may be a monetary settlement, the monetary aspect may be secondary to the owner who had a lot of emotions tied up with the guns as well. There is little chance money can replace your Sears and Roebuck .22 bolt rifle you got when you were 7 and used to get your first rabbit. Such items are priceless.