SHulion
As you might already know I am one those does have a light coat of oil in the bore. Here in Idaho we have to hunt in some really lousy weather and so i do put a light oil patch down the barrel. Now I am talking a very lightly oiled patch. I have not experianced any accuracy problems with this procedure at all.
With a loaded gun, cause I leave mine loaded few weeks at a time in good or bad weather provided I feel that I have protected the load, I will check for the need of bore protection. What I will do run is run a dry patch patch down the bore to the bullet.... you can really tell if you need to do anything just by the way the patch goes down - if it goes down smoothy and uniformly - then I leave it as is... If I were to run a very - very lightly oiled path down I would run it about halfway - then follow with a dry patch to the top of the bullet - run the same dry patch a couple of times...
Anyway as best I can run write this is close to my procedure....
Should have added I shoot T7 - so if you are shooting a Pyro or real BP then all bets are off...