Originally Posted by
Grouse45
I can assure you, in 10 days of hunting in Colorado there's no sign of any rust in my Ultralite. I've left BH209 in my gun for the full two weeks of Buck season in PA with no signs of rust. I've never even come close to seeing any kind of rust on stainless Muzzleloader's. I also used to load 777 in my Encore for a week of hunting and never seen rust. So will it rust, I'm sure in time ecspecialy if you don't take care of your ML and don't use a good preservative in your barrel. But nothing I ever need to worry about and most shouldn't either ecspecialy with BH209
I am a 99% T7 shooter which is well known to be more corrosive than BH, and again in SS - GM barrels - oh and in Docs White rifles I have never had a corrosion problem. And I do not clean the rifle until the end of the season even after shooting POI check shots at the beginning of the year. I have complete faith in the bore treatments I use and the techniques of barrel care I have developed over time. BH concerns me even less than does T7.
I am not sure what may have deveopled in the bore of the rifle in the OP's post. But since the growth is probably located in the area where the bore enters the stock - I am concerned about some form of water or water vapor problem. maybe not even related to what ever type of powder he used.