depends on where you live. I live in a real hi humidity state. I coat the entire barrel with motor oil. I wrap a rag around my finger and dip it oil and give the entire barrel/receiver too a nice coat. I have never got a spec of rust this way. It wipes off real easy with a rag. Then a light coat of rem oil and wipe with another rag and your good to shoot again. I've gotten spec's of rust with Rem Oil on long storage for just a few months. I have 870 barrels that I've stored 10 years now without ever recoating the barrel and still no rust. Try it You'll like it. Now not every state needs this level of protection, but I promise you it works and its cheap. break em all Jeff
Brownells sells a long term storage sleeves/pouchs called bore stores. They come in different sizes and shapes. I have one for a pistol and one for a barrel. They are extremely thick and are treated to prevent rust.
I use Ballistol multi-purpose oil it seems to stay put better than Rem oil and anything else i have used so far so good.It runs $10.00 a can and does a lot.I also use it to lube my break open trap guns and after 3+yrs. still tight as new.Grease does not have a lot of lubricant in it and hard to clean up.Gene
Used "Rig" for 30 years, good stuff. Keep a "Rig Rag" coated with Rig grease in shooting bag to wipe off gun after shooting.
I keep one in the safe so I don't forget to wipe every gun and barrel that I put in the safe. It's the only Gun Grease that I use.