Metal Shine Texture(Blender)

Im building a gun a scar H to be exact but i want the rail part to have a metal like shinnies to it how to do this? i dont know this im very new to texturing
the rail the one that got red circle and also im not using any blender syled texturing i only created the uv layer and import it to gimp for edit

 

What i usualy use dDo to do metal. you need photoshop but ddo itself is free(the lagacy version). unity makes it shiny automaticly with the standart shader. if you want the other parts less shiny you can do this by making a metallic map.

 

i never heard of metallic map? can you explain it to me

 

I never really used it myself, but its basicly a grayscale image and the lighter the colour is in the map, the more matallic it will look on the model. so you can just paint it. you can make the shinny parts white and the less shinnny parts grey or black

 

You need to confirm what you are using for the shader in Unity. If it indeed is the Standard shader, you need to learn how to use it. If you are using legacy shaders, you need to learn about those too. Either way, we need to know so we can explain exactly what to paint where. In either case, you can easily do it yourself in GIMP. It is a matter of knowing what to paint on what map.

 

if you want some parts of your mesh shine like worn metal, you must make a roughness/smoothness map
see docs for roughness maps.
the best option to make some neat worn metal, is to use a soft that paints on 3d models (zbrush, 3dsmax , mudbox, sculptris...and others).... use it to paint the worn edges in black and white, the take that first map in photoshop to refine the texture... trials and errors..