pluckit

OK so I think I have figured out that you are shooting a Blued gun steel barrel.... If that is the case you are much more suseptible to 'flash rust' in the bore if it is not protected by something, especially hunting in lousy weather let alone high humidity.

I am trying to think of how to word this without setting off a war... but even with that barrel you are not real suseptible to the corrosive effects of either T7 or BH - they both take time. So I think what I am trying to say is the tobbaco stained patches you are getting are 'flash rust' caused by moisture not the powder corroding the barrel although over a given period of time that will happen.

My suggestion to you would be give up on the alcohol, which can strip the metal of all protection, if you choose to use BH then use a slightly barely moist patch of a good bore oil after fouling or shooting, then a couple of dry patches. If you are shooting T7 use a regular Blue windex patch (just barely moist) to clear most of the fouling followed by dry patch - then a oiled patch as described above.

This should provide you with bore protection....

just a thought....