What are my options for treatment of a rifle after a magphos park job?  Its for a 3rd stringer that wont get shot much, or be cleaned very often. Looking for good long term durability, is there such a thing?

Others may disagree but I have a 5 gallon pail of inexpensive non-detergent 30W oil that I submerse my parked parts in.  I will suspend them over the pail until the excess drips off and then let them air dry on newspapers in my shop.  All this is after I have sprayed them liberally with WD40 to displace the water and park solution.  If you are looking for real long term storage, you can still get cosmoline in spray cans from MSC and I'm sure there are other more contemporary products available such as Sheath or Bo-Shield.  Personally, I find the 30W bath works well to prevent rust on MagPhos.

YMMV

Rick

I suggest you use LPS2.  Unlike LPS1, which is identical to WD40, the LPS2 leaves a light coating.  I use it on machines, parts, etc..  LPS3 is like cosmoline.  You could spray something with LPS3 and leave it outside for a year.  Both -2 and -3 wash off easily with mineral spirits.