Single-shot

Single-shot firearms are firearms that hold only a single round of ammunition, and must be reloaded after each shot. The history of firearms began with single-shot designs, and many centuries passed before multi-shot designs became commonplace. Single-shot designs are less complex than revolvers or magazine-fed firearms, and many single-shot designs are still produced by many manufacturers, in both cartridge- and non-cartridge varieties, from zip guns to the highest-quality shooting-match weapons.

Read more about Single-shot:  Modern Single-shots