Farmall--The shelf collapsed--or rather, its brackets pulled out of the wall--but I wasn't home when it happened. Does that count?
Many of the boxes broke open, and I had hundreds & hundreds of empties from various lots, all pied together. (The loaded ammo stayed together rather better.)
Was so distraught when I discovered the shelf and contents on the floor that even Mrs. Smokey was sympathetic.
Some of the stuff never did get sorted out; just scrapped it and bought new brass.
The shelf is back up, on brackets so arranged that the wall will collapse before the shelf comes down again!! And twice as much brass on it now.