Thanks all for the great posts. I can't remember buying individual shells but I remember the first time my dad brought home a brick of 22's. Federals. I rationed them out carefully.
When I still lived in Sioux City we had a small hardware store a few blocks away. Until he closed in the 90's you could still buy one nut or one bolt from bins. Used to have a barrel of fishing rods and once in a while you could get a good one pretty darn cheap. Had wooden floors and two big sheepdogs that didn't seem to mind the customers.
There's still a pretty decent hardware store a few miles from my house where you bag and weigh your own nails and nuts and bolts. They carry just about everything from brake pads to Quickrete. Even have a small selection of hunting and fishing stuff in one short aisle.
