what seems to pop out is the tiling on the grey area, which is a very bad thing when it comes to texturing. have u looked at a reference which resembles to the gun? this is very important to do when you want to create good textures.
the other thing is to try and draw out the shading and shadows, or just copy and paste a gun image on it -_-'
the other thing is to try and draw out the shading and shadows, or just copy and paste a gun image on it -_-'