Before we start creating our custom weapons, we will first require the models and sound effects that are needed for our project. Of course, you could model them yourselves, but it would require modeling knowledge (and the knowledge of using 3D modeling software such as Blender, Autodesk's Maya, or 3ds Studio Max), which is out of the scope of this book. For simplicity, we are going to use some free assets that you can obtain from the Asset Store.
If you would like to build a gun of your very own, some information on making the model set up for UFPS can be found at http://www.visionpunk.com/hub/assets/ufps/manual/weapons.
To open the Asset Store inside Unity, we can go to Window | Asset Store from the top toolbar.
If you aren't already logged in, go to Log In from the top-right corner of the panel and enter the information that you put in when you created the account.
From the right-hand side menu, go to 3D Models | Props | Weapons | Guns and select a weapon...