Protecting and securing your machine guns from theft
Very, very few thieves are going to go through ANY trouble to move a safe.
They might try to tip it over. They might try to tip it onto a dolly. Most won't touch it if it appears strong/solid. Some will try pry bars, hammers and similar.
Few thieves will defeat even the most basic alarm system. A half decent home alarm with a door switch on the safe and maybe a magnetic sensor on the wall would be extremely difficult to defeat, coupled with a quality safe.
We could go down any road... XYZ could easily be defeated with a stick of dynamite, a backhoe and 3 days time..." Yeah... but who's going to do it?