CB900F, there's a working definition of safe, and a legal one.
There's also an insurance company's definition of safe. If your safe isn't what the insurance company says is a safe, then they will deny your claim.
Although some policies will allow the use of an RSC for the storage of firearms, they most certainly aren't allowed for the storage of insured valuables when a safe is required by the policy.
The National Bureau of Casualty Underwriters, which is now the Insurance Services Office, had defined classes of "safes", and which definitions of said safes are used by many insurance companies. The minimum definition of safe, is a class b, which has a 1/2 inch steel plate door, and 1/4, steel plate body.
If you research UL ratings you will notice that the word "safe" appears on some, but not on others. For example, on a TL-15 rated safe, the tag will say "Tool-Resistant Safe". On an RSC (gun safe) it will say "Residential Security Container." That's because an RSC is not a safe by insurance definitions.
I deliver a few gun safes a day for other retailers who are in the business. It absolutely amazes me some of the misconceptions that the people buying these gun safes believe. Just because it has a combination lock and a star handle, doesn't make it a bank quality vault.
They say "It weighs 800 pounds, nobody is going to walk off with it", while at the same time, my 140 pound self is wheeling it past them on a dolly.
They say "maybe if somebody had a few hours and some serious tools, they'd get into it". The types of safes used in Jewelry stores are only rated at 15, 30, and 60 minutes and weigh thousands of pounds. RSC's are rated at only 5 minutes with a hammer and a screwdriver. They won't keep anybody out for hours. Most gun safes can be torn apart is under 5 minutes using a big hammer, axe, pry bar, or combination of the above. Somebody on this forum in another thread said it best.....lock the hammers, axes, and prybars inside the safe.
They say "my insurance company knows I have a safe", but they don't know what the insurance policy requires that safe to be, and are using their own definition.
You buy insurance for a reason. You buy a safe for a reason. You own guns for a reason. Having a claim denied, your property stolen, and your guns gone defeats that purpose, and flies in the face of common sense.
The moral of the story: do some research, get it in writing, and cover your ass. If an RSC is acceptable, in writing, from your insurance company, great. If you only need to keep kids out great. If you're keeping a $50,000 gun collection inside, better think again.