Gold sentinel M16's from fast tech

[tobacco-kills]

so i ordered a gold sentinel m16 from fast tech. Its ok, I have to say I absolutely hate the springs and threading.
Its horrible. Also when i first got it was actually nice and polished. Everytime Id use it, it would rub off some time of weird oil
on my hand. And now the gold sparkle on it had faded after 1 week and it looks like a bronze rust color? what the hell happen to it?
does anyone have any experience with these?

 

[E_DeCastro]

i used case resizing lube on the threads and as far as the finish, that's the way it goes for brass. no choice. get some brasso and get to polishing.

 

[Harlen]

If you wish to keep it nice and shiny you will need to coat it with polyurethane but you got too shine it up first and clean it before you do that

 

[Jayvaps]

brass oxidizes.