I spent nearly a year watching every video review on every safe, reading every article, and driving all over to actually put my hands on the safes mentioned in the reviews and atricles. It was a lot of time and work, but I wanted to make the right investment and get the most value for my money and I'm glad I took the extra time to do it. I would have to write you an entire book on here to relay the knowledge I learned along the way, but I'll try to keep it as short as possible.
Fire is your biggest threat. A 1/2 hour rated safe is basically no protection at all and is a complete waste of money. Pay attention to the temperature rating that the company tests the safe to get their fire rating and how long the safe is actually exposed to high temps. There is no standard testing method and a lot of the ratings are BS because they slowly ramp up to the rated temp and stop. A good test reaches the rated temp faster and holds it there for a longer period of time during the test. I would recommend a safe with a minimum of 1 hr rating. Of course the longer the better. A house fire will never reach and maintain the temps of 1200+ degrees for very long in one spot (meaning around the safe), maybe 10 minutes, but the better your fire rating is, the cooler your objects will stay inside the safe during that time. If everything in the safe reaches 400 degress for 10 minutes during a fire, pretty much everything is lost except for things made of metal. Again, pay attention to the temperature they list their fire rating.
Next is theft. A good sturdy safe with a good fire rating is going to be very heavy. If the safe you are looking at says it will hold 30 or 40+ guns and only weighs 500 to 700 lbs, it's probably a worthless tin can. You always see safe manufacturers toting about how pry resistant their door is. That's great, but the body is the weak point of a safe. Most cheap safes only have a 12 gauge steel body. Very easy to cut through with a grinder. Look for at least a 9 gauge body. No safe is uncrackable, but the key is to make it take a thief more time. More time means there's a better chance they'll get caught in the act. A heavy safe also means that a thief isn't going to be able to haul the safe off on a dolly and work on it somewhere else. That being said, a safe should weigh in excess of 1000 lbs to avoid this happening. Also make sure the safe is lagged to concrete or a very sturdy wood structure. Framing around the body of the safe and adding insulation and sheet rock will increase the fire rating and also make it harder for a thief to get at the body of the safe or even move it to do so.
Look at the mechanism used to lock the door bolts and where the door bolts are located. A good safe will have locking bolts on all 4 sides of the door and use gear driven locking bolts. Cheap safe's have bolts on two sides and use a cam drive system.
You also want a 1/4" steel plate on the door if you can afford it. Most cheap safe's have doors that "look" thick, but they are just fire board wrapped in the same cheap 12 gauge steel used on the body. Very east to cut and drill through.
There's a lot more to know and look for, but I'm getting close to making this post into a book so I'll stop there.
All that being said, I went with the Steelwater Xtreme Duty 72" tall 45 gun 2 hr fire rated safe. It has everything you'll ever need to protect your valuables and firearms for many lifetimes.
-The 2 hr fire rating is tested at 1875 degrees, not the 1200 degrees used by lesser quality safes.
-It has a 1/4" steel plate door, gear driven locking system, and 18 - 1.5" locking bolts that encompass all 4 sides of the door.
-The body of the safe is constructed of 9 gauge steel.
-The total weight of the safe empty is 1250 lbs.
-The price is very affordable and the quality is second to none. I have had my safe for over 2 years now and absolutely love it. I am in and out of the safe all the time.
-Steelwater also offers a military veteran discount and free cubside delivery depending on where you live.
Here's a link to the Steelwater Xtreme duty safe I have. This thing is an absolute fortress and is much cheaper than anything even remotely comparable on the market. Their warranty and customer service is second to none as well. I called them about one of the door lever spoke handles no quite threading in all the way and they had a new spoke to my door in about 3 days. No questions asked!
https://www.steelwatergunsafes.com/product/steelwater-xtreme-duty-2-hr-fire-hd724228/