I find the best way to store a rifle for an extended period of time is muzzle down, so oil can't ruin the bedding or stock. A foam case is a no-no. What I like to do is take synthetic grease, put a very light coat on all exterior metal, oil the barrel, and then wrap the rifle with plastic wrap. Any strong rolled plastic sandwich wrap works. Then I secure the plastic wrap with electrical tape. It is a bit of work but if you plan on storing the rifle for any extended time period this is one of the best ways. I never found rust on a rifle that was stored this way.
There is an old reliable product called RIG that will totally protect your firearms from rust. For short term I use a spray called Rust Prevent from Shooters Choice. NEVER store any firearm in a soft guncase if you can avoid doing so, just not a good idea. Having said that I have done it lots of times, but always shoot Rust Prevent all over the exterior and run some on a rag down the bore.
I have seen rifles get a coating of rust in about 24 hours from being in a soft case that had wet lining.
I have a lightweight sporter that has a blued barrel, last year it started to get rust from humidy ect, I open the gun case yesterday and there was some surface rust again, I sanded down the area and cold blued the area, I apply oil and it dosen't seem to hold up, are there any better protectants I can apply to the barrel to stop this nuisance.