Smith et Wesson model 78G
The Smith and Wesson models 78G and 79G are vintage models of air-powered pistols. Each model chambered either a .177 or .22 caliber pellet.
The S&W G-series pistols were designed with attention to accuracy and weight in particular, making them idea in developing short-range marksmanship skills while using a less-penetrating, air-driven pellet as the projectile.
However, as these vintage airguns were manufactured in the '70's (when the research behind airgun technology was less sophisticated) there are several drawbacks, including the fact that each model can only chamber one pellet at a time, requiring reloading after each shot.
Also worth noting is that, while each model uses small pellets driven by CO2 cartridges, an airgun is still a potentially dangerous weapon requiring attention to all the basic safety premises followed when using regular combustion-driven firearms.