at one time , I did all the stuff you all have mentioned.I have hunted all day fired and cleaned.hunt and fire the next morning , load and hunt and clean that night.it always shot and at the end of the season there was no damage to barrel.
Then one year I left it loaded for 4 mo. due to medical problems.it shot like new.My pistol was left till the next year.it shoot OK also.
This was guns that was loaded and not shoot(if you shoot that gun It Has to be cleaned;no mistake.don't clean and you got a messed up gun)!!![]

that being said,if it was shootin and not causing a problem ; Why was I doing all this cleaning??after that If I didn't shoot it I would leave it till the next year and shoot it befor the season and clean and load.(Never no problem) this was for 25 years or so.
For the last 15 or so years I have not had that problem.I have taken 2 or 3 bucks a year,so I have to clean and load again.

JMHO; if it has not been fired,it has been load properly,the powder should be just like in the can.it should not cause a problem.at least that has been my experence.I don't shoot my gun unless it is at a buck.or the next year,which ever come first.[8D]