Takedown gun

A takedown gun (typically a takedown rifle or takedown shotgun) is a long gun designed to be taken apart significantly reducing its length, making it easier to store, pack, transport and conceal. A variety of barrel, stock, and receiver designs have been invented to facilitate takedown. For example, the hinged design of many break-action firearms allows takedown. Some regular firearms can be modified to allow takedown after custom gunsmithing.
Rifles.
American gun manufacturers including Marlin, Ruger, Savage, and Winchester have made takedown rifles since the late 1800s. Some early examples include the Browning 22 Semi-Auto rifle, Remington Model 24 and Remington Model 8 made by Fabrique Nationale and Remington Arms.
Shotguns.
Most single barrel and double barrel shotguns readily break down into separate buttstock, barrel and forestock and are often transported cased as takedown guns. Among repeating shotguns, the Winchester Model 97 and Model 12 shotguns were factory made as takedown guns. Savage also makes a series of takedown over/under rifle/shotgun combination guns.
Survival guns.
Survival guns such as the ArmaLite AR-7 may be disassembled and its barrel, action and magazines stored within its plastic butt-stock. This lightweight 2.5 pound, .22 caliber, semi-automatic rifle measures 35 inches overall when assembled, 16 inches when disassembled and can even float. Although the AR-7 was designed as a pilot and aircrew survival weapon, it is commonly used by target shooters and backpackers, and is frequently stowed away in vehicles and boats.