Results of an EF5 indicate that any building not made of masonry will be ground up to dust, including most of the contents. All that can be deposited from a few feet to literally counties away downwind - photos from Joplin were found in farm fields near Republic, MO almost 50 miles away.
Gun safes in basements below grade largely survived, above grade they were ripped from the concrete and tumbled repeatedly becoming unrecognizable. Same for cars, we lost 5,200 of them and you had to id by VIN in many cases. A safe full of guns? Roll it end over end lifting it into the air ten feet repeatedly and it's going to beat them like a concrete mixer. A gun cabinet - those things we buy that aren't 1/4 plate steel - will likely burst open scattering the contents wherever. That is what happened to Walmart, Academy, and a sporting goods store. The larger box stores were masonry, the Walmart lost the block sidewalls and that separated the roof exposing the contents. Winds were estimated at 200mph, hurricanes can exceed 177mph and they sustain it for a much longer duration.
Anything you want to preserve needs to be stored below grade and in a flood resistant manner. Otherwise kiss it goodbye. While looting largely came from out of towners, most of it was shut down in the act as law enforcement was on the scene in high numbers about as fast as the looters could arrive. Most looters were looking for jewelry or other high value small items. If anything the guns left in the debris are subject to being returned to you directly or turned over to authorities by others like you in your neighborhood. Everyone turns out to help, all suffer equally.
If anything, fire is the larger problem year after year, homes not kept up to code have increased risk of fire as time goes by, and fire destroys a gun collection with no remorse. It can and will happen 365 days a year, not just bad weather season. Space heaters, overloaded circuits, kitchen accidents, and using flammables in an attached garage are all contributors.
Many Americans live in stick built frame homes on grade, it's the least optimal type and come fire or high water it's toast. You are left with the foundation and some debris.