My reloading bench is sort of in the middle of the basement because of all the demands for wall space from my wife. It's approximately 3x4 feet with two shelves. The bottom shelf is reserved mostly for ammo in waterproof ammo cans from Cabelas. The extra weight keeps the bench from moving.
The best I've seen is a friend who noticed all the empty space under his concrete front porch when his house was being built. For an extra $1500 the builder knocked a hole in his basement wall to under the porch and converted the space to a gun room. Concrete walls, floor, and ceiling. A safe door for a door (another $1500). It's probably 15 or more long and at least 10 feet wide at it's wide point. The entrance is concealed behind a screen in the utility room.
Pretty slick. However, he's so proud of it he shows it to everyone who comes to visit.
He has a gun safe in the garage too, in case he runs out of room. It could happen. He has 1000 rounds of .50 BMG alone on one shelf.
"What kind of man would put a known criminal in charge of a major branch of government? Apart from, say, the average voter." - Terry Pratchett