I have to wonder how many Rem 870 shotguns were made. The number must be in the millions. Just about everyone I've hunted with in the past 20 years had one. They might not have hunted upland with it but they had one to beat up hunting waterfowl. I bought a new one in 1970. As far as I know they were building them before that and have been building them ever since.
Edit
Just googled it. 10 million by 2009. Introduced in 1950.