I have several rifles that I (and previous owners) have put a lot of rounds through. Looking at the gas tube interiors, there appear to be thin, longitudinal lines of rust along the interior of the “flutes” where, I’m sure, the piston head has scraped off the original finish (I assume the interiors had been painted). My question is, does anyone here ever actually bother removing that rust (naval jelly?) and/or repainting the interiors?