This is a paid asset, but now you can download Customisable Weapons Pack for FREE, but please remember 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
Customisable Weapons Pack v1.0
A set of weapons with custom shaders ideal for making new faction based colouring, tweaking metalness and glossyness.
Colours are driven by vertex colour which are edited in your 3D program of choice, this has been done for you with this set and now you can easily make up new colours without the need to edit textures.
This version contains:
A Battle Axe
A BroadSword
A Sword
A Dagger
Textures are hand painted in 1024*1024 and 3 extra material variations have been created per weapon.
More weapons will be added to this pack based on request or simply to expand the usability of this pack. You can also use the shader on anything you wish, simply give your meshes vertex colouring in the form of pure values Red,Green,Blue,Cyan,Magenta and Yellow.