The Remington Model 870 is a pump-action shotgun manufactured by Remington Arms Company, LLC. It is widely used by the public for shooting sports, hunting and self-defense, as well as by law enforcement and military organizations worldwide. Development The Remington 870 was the fourth major design in a series of Remington pump shotguns. John Pedersen designed the fragile Remington Model 10 (and later the improved Remington Model 29). John Browning designed the Remington Model 17 (which was later adapted by Ithaca into the Ithaca 37), which served as the basis for the Remington 31. The Model 31 was marketed as the “ball-bearing repeater” and was well-received, but its many machined and handfitted parts made the gun expensive to manufacture. Consequently, it struggled in sales compared to the Winchester Model 12. To achieve better sales, Remington produced the Model 870 in 1950, which was more modern and reliable in its construction, easy to take apart and maintain, and relatively inexpensive. The 870 was a commercial success. Remington sold two million guns by 1973 (ten times the number of Model 31 shotguns it replaced). As of 1983, the 870 held the record for the best-selling shotgun in history, with three million sold. By 1996, spurred by sales of the basic "Express" models, which were added as a lower-cost alternative to the original Wingmaster line, sales topped seven million guns. On April 13, 2009, the ten millionth Model 870 was produced. Design details The 870 features a bottom-loading, side ejecting receiver and a tubular magazine under the barrel. The gun comes with a plug for migratory bird hunting which reduces the magazine's capacity to two rounds. It has dual action bars, internal hammer, and a bolt which locks into an extension in the barrel. The action, receiver, fire control group, safety catch and slide release catch of the Remington Model 870 shotgun are similar to those used on the Remington Model 7600 series pump-action centerfire rifles and carbines. The basic fire control group design was first used in the automatic 11–48. Twelve gauge stocks will also interchange on the older 12-gauge-sized 20-gauge receivers, although modification is needed to fit the smaller sized 20-gauge receivers employed since the late 1970s. Several parts of the 870, such as buttstocks and magazine tubes, will interchange with the semi-automatic Remington 1100 and 11–87. The original 870 models were offered with fixed chokes. In 1986 Remington introduced the