Fallout 4 allows players to construct elaborate settlements with a noteworthy level of automation, and one fan used this feature to build an impressive ammo factory for their pistol.
While melee builds are possible in Fallout 4, especially if one can get their hands on an Instigating Super Sledge, most players tend to opt for ranged weapons during their first playthrough.
As a result, ammo becomes one of the most valuable pieces of loot that the Sole Survivor can come across in the Commonwealth, especially if they don't have access to the Contraptions Workshop DLC.
Not only is ammo in Fallout 4 weightless, but unneeded ammo types can also be sold to a vendor for a decent amount of bottle caps when starting out.
However, unless players have already decided on the type of weapon that they'll wield in Fallout 4, it's generally useful to keep a healthy stock in one's inventory.