"Mossberg's 500 appears inexpensive" (it is cheap), yet it is an incredibly dependable shotgun. "More than 9,000,000 have been produced since 1961, and they have dutifully served in the field, in squad vehicles, in the military, and alongside the bed ever since," Bourjaily said. "The 500 has also served as an incubator for new ideas." In fact, the original 500 incorporated many modern features that later appeared in other shotguns, such as a folding stock, a pistol-grip handle, and a cocking indicator from a Lewis machine gun-the first commercially manufactured gas pistol. The 500 was introduced in 1961 and discontinued in 2001. However, several modifications have been made to the design over the years, most notably a drop-in shell holder that allows users to replace the standard box of 20 shots with a five-round magazine. In addition, several aftermarket manufacturers produce parts and accessories for the Mossberg 500. Bourjaily says that "the Mossberg 500 is still one of the best values in all of firearms today." In conclusion, the Mossberg 500 is considered by many to be the perfect home defense weapon because of its reliability and affordable price tag. These guns are also good for people who want a versatile firearm that can shoot shells from both sides of the chamber.