MudBogger,
Been to that part of Oregon and your humidity is low..but it's great country.
Try the superglue treatment, and bring the little rifle indoors and out of the case where the wood can breathe.
This time of year, the interior of that jeep might get over 100F this time of year and things are dry down there( look at the NF fire danger signs)

I've seen all sorts of woodwork and done alot also.
Seen perfectly good well made heirloom hardwood furniture literally come unglued when it travels to a very low humidity area from where it resided for years in the eastern states...

Fitted wood on steel will move and shrink( or expand) ( the steel, screws etc don't change uch or at all) depending on the MC changeing.Moisture content of wood WILL change over days and weeks and gravitate to the ambient humidity to a corresponding moisture content.
Keep your firearms stored in an ambient that's about 50-60% relative humidity and they'll do fine, neither rusting corroding on the metal end nor shrinking-swelling on the wood parts.
Going afield even in extreme weather with a properly finished wood stocked firearm doesn't pose serious problems, so long as it doesn't stay there over long or be neglected with the drying, cleaning, oiling & wax when it comes home.
IF possible, remove the buttstock from the receiver tang to do the superglue treatment.Wipe off all excess superglue as it doesn't dry - cure in air well at all, but only when exposed to moisture and tight fitted joints.
A drop on a slightly damp pair of fingertips and a drop between two pieces of very dry nedia will demonstrate when the CA glues work..and when they don't .Jim