so i was looking over my dallra body.
it has some stuff/ corrosion? on the inside that looks like rust but without the rust color.

if i take a nice polishing compound,ALLBRITE to this, i cant feel the roughness of corrosion.

is there a good way to cure this?
i dont even know if it is corrosion, so here are some good close pics.

let me know if any of you have had this issue, or know what the hell is going on here.