There are very few safes on the market that are going to protect your guns in a fire. I was involved in disaster restoration for a couple years and saw house fires first hand a few times a week. I saw high dollar 12-15K safes fail just like the $250 stack ons. Your safe may have a fire rating but the smoke is going to destroy your contents long before the fire does. House fires get extremely hot and the smoke is full of heat, toxic fumes and LOTS of moisture. The somke will penetrate the seams in your safe in seconds and will instantly etch the metal on your guns, accelarate rust, corrode, etch your glass on optics, and stink up the plastic or wood stocks. Your best bet is to buy one that has a solid door on it to prevent burglars and kids from breaking into it.
The best thing you can buy to protect your guns is insurance.