Storing inside a case is a crappy situation. Any moisture stuck between the foam and rifle will increase the chance of rust building up.
Without a safe, I store mine loose in the closet. It keeps air circulating, and easier to check once a week to make sure everythig is good to go. I wipe everything down with a rag with CLP on it, then a dry rag, and run a lightly oiled patch through the barrel (a drop or two, don't want it to be runny). Any dust or pet hair gets brushed off with a paint brush.
I've done this for 20 years on my (blued) .22 and never had a problem. Also do it with my Garand and SOCOM for over a year now. Parkerized weapons you shouldn't have to re do except every few years. Blued need to be rewiped every few months.
If you HAVE to keep them stored in the case, and it's for long periods of time, you can vacuum seal them with a coat of oil on them. Kind of like the military stores them packed in cosmoline.
In any case, the trick is to put a very light coat of oil on them.