I have 2 rifles stored in foam encased hard plastic cases that remain in my bedroom when not in transit or in use. My bedroom contains a fussy lady that likes warmth and limited fluctuation in temperature. Took both rifles out for a play yesterday - an Air Arms 400 Superlite (2 yrs old) and a Daystate Hunter Classic (1 yr old). Glorious day for a few hours on the range and after 2 months without spitting a JSB it was good to be out. When putting away both rifles I generally give them a once over. This time I noticed a few dirty spots on the barrell of the Air Arms. I assume these are rust spots??? How do I deal with them? How did they appear? How do I prevent this from happening again? Any advice appreciated.