NPCs should be able to use ranged weapons from other mods, tried to use Timeless and Classic guns and they just them as melee weapons

Ranged weapons need to be implemented correctly and extending the crossbow or bow.
If they are custom items with mixins or so they are not really supported.

Could you please share the Curseforge link of some of these mods you want support for, so that I could check them more in detail ? Thanks.

Here is the github link of "timeless and classic guns",https://github.com/286799714/TimelessandClassics_Reforged.

I suppose just make sure those guns or other mod's ranged weapons can be rendered, and the bullet can be customized, like "customnpcs", you dont need to make it compatible a single mods.

Thanks a lot for the link.
Unfortunately the weapons are not implement correctly and implemented as "custom item" (not as "RangedWeapon") with some mixin:

See:

• https://github.com/286799714/TimelessandClassics_Reforged/blob/b3e93d1950999ba5c0c95fe1b410973c7541a789/src/main/java/com/tac/guns/item/GunItem.java#L32

• https://github.com/286799714/TimelessandClassics_Reforged/tree/tac-new-1.18/src/main/java/com/tac/guns/mixin

For this reason they are not supported out of the box.

However I like your idea and will check if I could just render them correctly and using a standard projectile.
At the moment there is no option to define "custom" bullets or projectiles, maybe I will add a standard pullet for such weapons for now.

With the next update I will add a basic support for gun for testing.
However they will shoot arrow until I implement a custom projectile like a simple bullet which is covered by in another feature request.