I keep a ziplock bag of patches with windex applied to them. Not a ton just a few. I also have a few that are pre loaded with the oil I use which is remoil. I left my oil in my base camp and didn't have any. I used breakfree and ended up with a hangfire that cost me a elk. I won't use untested gear again.
After swabbing with the windex patch I use a dry patch. I run it down and back out. I flip it over and push it down and pop a couple caps. What I want to see is a burnt patch. If the patch is only slightly burnt pop a couple more. Make sure the nipple is clear. Then I run the oil patch down. Make sure it is not overly wet. I carry a jag, A nipple wrench, spare nipple, a patch puller and a bull puller. All of that fits in a small bullet box. My guns shoot best with a clean bore. If I have to shoot like your post asks I want to get it back to clean as I can get it
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For wet weather I cover the muzzle with electricians tape. On my inline when hunting I cap the nipple and cover the opening in the action with tape. Don't worry about taking off the tape for the shot. The air being forced down the barrel will remove the tape before the bullet gets there.
My pack is also a scabbard for my gun and I have a rain fly that goes over the gun,pack and everything.
My Renegades and Hawken are treated the same but the nipple is tougher to keep dry. I have a rubber cap that fits over the nipple. Some use what is called a cow's knee. It is leather and goes over the whole area where the lock is all the way around.
Ron