[meatloaf]

I know of situations where safes that have been bolted to the floor were still ripped out of the house. The best idea is to buy a cheap safe that can be removed. Add an old car battery or two for weight. Hide your firearms someplace within the structure of the building.

[Cold Heart]

My neighbors house was broken into when I was a kid. Neighbor had a small, heavy safe bolted to the floor in a closet. Took the thieves all night to rip out the floor to get away with the empty safe.

[AlaskaErik]

Add an old car battery or two for weight.

I prefer to add ammo for weight. It's much more useful.