This is a paid asset, but now you can download Fps Gun Pack for FREE, Please keep in mind this package is provided only for learning purposes or to be able to test before buying the product, NOT FOR COMMERCIAL PURPOSES.
Detail this asset from Unity Store: Original Link
Fps Gun Pack v1.0
First person weapons pack.
Includes a pair of first person arms.
Includes 4 weapons:
-Pump action Shotgun
All models are high quality next gen assets with pbr textures.
All guns are animated.
These animations include:
-Aim down sights
-Aim down sights fire
Comes with a first person controller with all the guns are the arms set up on it.
Comes with custom camo shader that allows you to add your own camo textures to the plastic parts of the guns.