Welll...for one I have that EXACT MODEL of pistol safe (the Stack-On one) and it says VERY CLEARLY in the instructions that it must be bolted to a wall and shelf - the "drop" hack should not even be able to happen. But just to test, I pulled it off the wall and did that drop/whack test many times and the door did NOT open.
But I also bolt all my safes to the building.