My wife often rearranges our cats. She picks them up and places them at points in the house that meet some incomprehensible scheme of things. The cats, being well mannered, go along with this and then go right back to where they were.
This is the way that gun oil behaves. You put it where you think it ought to go and then it goes where it pleases, which is usually into your stock, or your trigger, or your receiver. That is why we have grease. Grease stays where you put it.
Here is a brief review of some different kinds of grease I’ve found useful.
At the head of the list is RIG, which stands for Rust Inhibiting Grease. The stuff has been around since before World War II, and is the best thing I know of for preventing rust long-term. (It does not lubricate.) RIG is sold with a sheepskin pad, called a RIG Rag. You work a little into the wool and then wipe your guns. I’ve never had a RIGged gun rust on me.
Next is white lithium grease, which is sold in hardware stores. It’s for lubrication, not rust prevention, and is best used on shotguns, where it clings like grim death. Trapshooters love it, except when it comes time to get it off. Lubriplate is similar, and just as effective.
Birchwood Casey Choke Tube Lube, when applied to your choke tubes, will keep them from sticking. It seals the threads so all the nasty stuff can’t get at them. It also makes sensational stains on clothing.
Brownell’s Action Lube Plus is highly useful at any point where there is friction, such as bolt lugs, or the front rings of rotary-dovetail scope mounts, or pistol slides. Use sparingly.
Cosmoline is still around after who knows how many years, and will still do the job, although it is a nightmare to remove.
And a safety note: I don’t believe in greasing the bore of any firearm. If it’s clean and oiled it won’t rust, and hardened grease that you’ve forgotten about can cause dire jumps in pressure. I know of a truly frightful accident that was caused at least in part by old grease in an Enfield bore.