I remember finding old, corroded unspent .22 shells out in the fields, growing up on a farm. It wasn’t unheard of to dump a partial box of those shells in your pant’s pocket when you went out varmit hunting. Occassionally, a couple would drop out.
Back then, I used to buy a box of 50 of the Rochester brand, for around 80 cents. Cheap as dirt, and almost as plentiful too.
Yes, they are kind of like pennies. You keep a bunch in your pocket and every now and then one gets dropped on the ground.