[quote=“Aluminumfoil”]Many items and recipes in the game are just there because they can be, not because they have any intended niche.
Take a region like the US northeast where there’s about one gun for every human and remove 99% of the people, and you’re left with 100 guns per surviving person… and that’s just counting civilian firearms.
A decently maintained firearm can remain functional for centuries. Ammunition should rapidly become scarce after the end of industry, but not guns. People will be recycling perfectly functional rifles for their steel long before anyone bothers to make a pipe gun in postapocAmerica.
Heck, they might even probably be using rifle barrels as makeshift pipes :D[/quote]
The problem with pipe guns is that most in-game firearms never receive damage from rust, overheating, or extended use. Most real-world guns developed after the handgonne are made with springs that tend to weaken after heavy use. Also, guns must have their barrels replaced after x number of bullets have been fired, due to barrel wear. Because of this, pipe guns, especially the Pipe Rifle: x caliber series, lack a strong niche. If a weapon repair system similar to the version in Fallout 3/New Vegas were implemented, then homemade guns would become useful after most reliable sources of factory guns have been exhausted.
A fix for this behavior would be for the game to check the age of the world when generating new terrain and reduce the amount of technological spawns as the world aged, with exceptions for the areas surrounding functioning communities that preserved or restarted industry.
[Edit: ClockworkZombie phrased it better than I.]