Survival rifles are built to be carried for a long time and fired rarely: light, short when packed, and simple enough to work after years at the bottom of a pack or a bush-plane kit. Most are .22 rimfires, because the ammunition is small and light and still takes small game. The Henry U.S. Survival AR-7 is the best known. It descends from ArmaLite's AR-5, a bolt-action .22 Hornet the U.S. Air Force adopted as an aircrew survival rifle, and it stows its barrel, action and two magazines inside its own ABS stock. The Chiappa Little Badger is a single-shot break-open rifle with a wire stock that folds in half. The Chiappa M6 and TPS Arms M6 follow the Air Force's M6 aircrew weapon, an over/under with a rifle barrel on top and a .410 barrel beneath, and the Savage 42 takedown is the same over/under idea with a conventional stock. Marlin's 70PSS Papoose is a stainless takedown semi-auto that packs into a carry case.