RE: Using the Montana X-treme products
I've read a lot of the post on this and there are some good points (i.e.: Semisane's when is it clean enough) Actually, I feel the more you crudcan get out of the barrel the better off you are. Even if your POI changes. You can always readjust the sights. Now, if there is a major POI change from the first to the second shot then you may have a problem. But I don't see that happening either because with the BC, there should be LESS fouling and a spit patch should remove it easily.
IMO any carbon residue in the barrel is a point for moisture to collect, hence rust to start. A coating of gun oil or other rust preventative should stop this from happening if that area is treated. But not having the residue there is even better.