Hey ssaki2006 , I'm not planning on doing a full tutorial for this revolver in particular, but these courses can absolutely get you to this type of result:
https://cgcookie.com/course/mesh-modeling-bootcamp
https://cgcookie.com/tutorial/creating-3d-assets-for-virtual-reality
https://cgcookie.com/course/modeling-weapons-for-a-first-person-shooter
https://cgcookie.com/course/texturing-weapons-in-blender-and-substance-painter
As for VR game mechanics, these courses can help:
https://cgcookie.com/course/fundamentals-of-virtual-reality
https://cgcookie.com/course/fundamentals-of-weapon-mechanics
Happy creating!