Garden gun

Garden guns are small bore shotguns commonly used by gardeners and farmers for pest control. They are made to fire small gauges such as .410 bore, 9mm Flobert, or .22 rimfire shot shells. They are short range shotguns that can do little harm past 15 to 20 yards, and they are relatively quiet when fired with rimfires. These guns are especially effective inside of barns and sheds, as the low velocity small shot will not shoot holes in the roof or walls, or more importantly injure livestock with a ricochet. They are also used for pest control at airports, warehouses, stockyards, etc.
.22 Rimfire.
In North America, garden guns are usually chambered for .22 Rimfire and the most common cartridge is a .22 Long Rifle loaded with No. 12 shot. From a standard rifle these cartridges can produce effective patterns only to a distance of about - but in a smooth bore garden gun this can extend as far as .
Example smooth-bore firearms include the: Marlin Model 25MG, 
Remington Model 511SB, Winchester Model 67 and the Henry Garden Gun.
9mm Flobert.
In Europe, garden guns designed for the 9mm Flobert rimfire shotshell cartridge are common, and face very little to no restriction, even in countries with strict gun laws. Its power and range are very limited, making it suitable only for pest control. Fiocchi-made 9 mm Flobert rimfire ammunition uses a 1.75" brass shotshell firing 1/4 oz shot of No. 8 shot with a velocity of 600 fps.
Examples include the Chiappa Little Badger Shotgun
.410 bore.
Small .410 gauge shotguns such as the Snake Charmer, Rossi Tuffy, and H&R Tamer are also commonly used by gardeners and farmers for pest control, and are sometimes called "garden guns". .410 shotguns loaded with shot shells are well suited for small game hunting and pest control; including rabbits, squirrels, snakes, rats, birds, etc.