Good test, Cayugad. I must say I am also a little surprised. There has got to be some sort of internal condensation factor going on here. Particularly in the Knight Disc rifle. I generally leave my rifles loaded for the entire season out here in the semi-arid west. No problems. Our MZ season is in September, so we don't get the cold temps like northern Wisconsin in January. Few places do . . . other than Fairbanks AK
I also am a firm believer in tape over the muzzle. Did you use your usual finger cot on the muzzles during this test. Maybe it wouldn't have made any difference . . .