Some notes from my research into gun safes...
Lower cost safes are built to be either fire-resistant or burglarly resistant. Safes that do both are going to be more expensive.
Fire resistance is measured as the ability to maintain a safe temperature inside of the safe for a given period of time, in a fire of a given temperature. As far as I can tell there is no required national standard; but UL does have standards to achieve a UL rating a safe manufacturer has to use a UL test protocol. Big note: A safe that is advertised as having been
tested against a UL standard does not mean that it
meets the UL standard - i.e. it didn't pass. If it passed, it will state the temperature it can withstand, and for how long, e.g. 1200 degrees F for 30 minutes. Fire safes may have a lock, but they are not rated or really meant to be burglar resistant.
Fire safes that protect paper documents have to keep the inside temperature under, if memory is correct, 400 degrees, and I believe most (good) ones aim for 350, again for a given length of time. Electronic media, like CDs, hard drives, and such, are more vulnerable to heat than paper -- I believe the threshold is 250 for them, and the safe will be specifically rated for computer media. I have not been able to find out what the accepted safe temperature for firearms is -- I would think a paper-rated safe would be good, but wonder about the finish on fine wooden stocks, or some the synthetics used in firearms.
Fire safes may also have a drop test rating -- they are heated to a prescribed temperature, then dropped 30 feet onto a pile of bricks resting on a concrete floor. This is to simulate falling from the second floor into the basement during a fire.
Burglar resistant safes are made do do that -- resist entry by burglars. With enough effort, any safe can be opened eventually, so the standards are for how long the safe will resist entry. "RSC" safes -- Residential Security Containers -- is the formal name for lockboxes like you buy at WalMart and Office Depot. No real standard, just a metal box with a lock. TL-15 rated safes are supposed to prevent entry by burglars using common hand tools (including hand power tools, I believe) for 15 minutes. TL-30 is for 30 minutes. Again a test that has been "UL-tested" but does not have a rating likely did not pass the test...
Again, safes that are both fire-rated and burglar-rated have to meet both sets of standards, and will of course, cost more. So depends on what you want.
You have to decide what you want, and then see if the Sentry safe for $799 does that. The ad says it is a "Firearm" safe, but given what Locksmith said about moisture and rusting, you may want to investigate that claim a little bit deeper. I see it meets the California rules for a firearm lockbox, but I don't know what those rules are, precisely -- I was under the impression it was to prevent child access more than burglar access, but I might be wrong.
Good luck!
elb
p.s. Here is an amusing video touting Ft Knox safes, where some guys drop a gunsafe with guns into a house with a crane, then burn the house down around it.
http://www.youtube.com/watch?v=9buR30A_0lk" onclick="window.open(this.href);return false;