I'm not quite sure what a "stack on" safe is, but I'll check into it.
Yes, I understand .... of course.... that thieves do not have to be careful and clean as they work. That is why, in my original posts here, I worry about the "ransacking" problem once they discover that this is a gun owning house.
I have a walk-out basement. If it was just a basement that was fully under the house, then I could possibly put a safe down there with very few worries about the truck-pulling-safe issues.
Those kinds of thieves are just going to get the stuff, though. Anyone that brazen, if they want to take the risk of being seen by my neighbors, are going to be difficult to defend.
Back to hiding my stuff outside, I would be AMAZED if they could find and take my stuff outdoors. Finding stuff in someone's house is downright child's play by comparison. That's why the outdoors was originally on my mind.