^"(how many significant digits do you mean by that?)"
Good question, especially since I'm usually the one bitching about indeterminate qualifiers like "reasonable." As in "reasonable gun controls."
I basically mean, "could the apparent loss of effectiveness be due to this level of cryo-soaking?"
I know there's a lot of back-and-forth about springs, as in "does keeping a full magazine affect the springs?" and the sometimes-answer: "No, it's the cycling of the springs that wears them out."
So there's a bit of spring lore/technology that's out of the bounds of my experience, and cryo-soaking at this level is one of them. I do know that "real" cryosoaking (~minus 320°F) relieves some stresses in rifle barrels and tends to make them more accurate, but we're only talking ~0°F here, and I'm sure there's no sharp cutoff where cold affects springs at X°F but not at (X+1)°F.
I do know that military hardware sometimes becomes unworkable in some cold-weather battle scenarios.
Terry, 230RN