There is Tear type ammo(good at ripping off components), fire,freeze,electric type ammo as well (obvious what they all do).
Some weapons have different uses and can only use certain ammo types. For example, in currently using the shadow hunter bow, its for short-to-medium range combat that uses regular arrows, tear type arrows, and fire type arrows but I also have another bow that for long range combat that uses regular ammo and tear ammo. It is slower but does more damage.
There is also another bow type(for example the War Bow) that does do immediate damage but rather causes a status effect. I personally dont use it but rather use the slings instead(kinda like grenade launchers)
You also have your tripcasters, ropecasters, a machine gun like caster for rapid normal type damage(so far there is probably an elemental one), etc. that have their own uses, in which some do damage and other are useful in other ways.
Also you can increase how much ammo you can hold of each weapon type, how many weapons you can hold, outfits, resources, etc in the modifications tab.