Lots of good input.
A few reoccurring themes on this thread:
1. 80 gun safes aren't 80 gun safes.
2. At some point a vault with a vault door becomes a better option than a bigger safe.
3. 2 safes may be better than 1 big safe.
4. Electric locks? I think the jury is still out on those. Personally, I would opt for a high quality mechanical lock (dial) even if I had to pay more money to get that option.
5. I once moved a safe from one house to another. I'll never do that again. The safe can convey with the house and a new safe can be obtained.
A few points that were touched on in the thread that are worth expanding on.
1. The safe MUST be secured so that it can't be tipped over. Don't rely on the weight of the safe to prevent its removal or toppling. The first part of just about any brute force attack is to get the safe on its back.
2. Water can be a danger. A small solid pedestal to hold the safe off of a concrete floor will help prevent condensation in/on the safe. Plus a small pedestal will save you from damage in minor flooding situations. Just a couple of inches of elevation can be the difference between an annoying plumbing problem and thousands of dollars of damage.
3. HIDE the safe. You can't steal what you cannot find.
4. Maintain strict confidentiality of security details. It is a sad fact that theft often involves acquaintances or family members. Even if they don't directly steal the property, they can leak security details to those that will. Everyone has that; Uncle, Nephew, Cousin, distance acquaintance - that is a problem.