I load my gun on a clean barrel and leave it loaded until I either shoot a deer or the season is over. Never had an issue with ignition or rust, even with pyrodex and #11's.

And fwiw, I'm not saying that you couldn't have a problem going from cold to hot... but in my experience its a non issue - at least in my knight inlines w/ss barrels.

I used to think that going from cold to warm (or hot) was taboo because it was all I'd ever heard in the 25+yrs of ML'ing. But after an unofficial experiment I conducted a couple years ago and doing this dozens of times over a couple month period, I had no rust or ignition issues. And this was going from sometimes single digits outside, into my woodstove heated basement (prob 75* or more). Personally, it doesn't worry me one bit anymore. I couldn't get a more drastic temp range, and if that didn't cause a problem, I don't know what will. And it wasn't one or two times... it was ALOT.
I'd always heard everyone say... never do that, its almost a guarantee of either ignition issues, or rust. Interestingly, I never had anyone tell me they actually HAD an issue doing this.

I'm not saying do what I do...but wanted to let you know my experience. My .02 fwiw

unofficial test thread