Another wild option if you're worried about the weather is something I've been thinking about doing to my rifles for a long time now: getting them treated with a salt bath nitriding process. The main pieces that is, like the barrel/chamber, bolt body, etc, but not the small parts like firing pin spring or trigger group. This is the same process that some handgun manufacturers have been doing for years, namely Glock, Smith and Wesson (for the M&P), and springfield armory for their XD, to name a few. It hasn't really caught on for rifles yet, but a few people are starting to do it. It basically will make any treated parts more rust/salt resistant than stainless steel or even chrome plating, as well as dramatically increasing wear resistance, such as for barrel life. A few companies do this process, such as Thermex in Edmonton (they call it their QPQ Liquid Nitriding process).
Someday I would like to get a gunsmith to disassemble all my rifles and send the main metal parts for nitriding then reassemble them

I don't believe it's too expensive, you'd have to call them to find out as they usually treat bulk orders for things like machinery, drill bits, etc... but I've heard numbers around the $80-$100 mark mentioned for a rifle, which would make it as much or less than many other surface treatment options. As a side note, I would break in a rifle barrel to make sure it's smoothed out any tooling marks in the throat before I treated it with a nitriding process, because the treatment makes the surface so hard it's extremely difficult to machine or work after that. Same goes for any gunsmith work you want to do first, like drilling/tapping, recrowning, etc, make sure to get it done beforehand.
As for ammunition that is already loaded, Trade Ex also sells and will ship 6.5x55, click on their "ammunition" link.
Cheers!
Red