Dale- The key word is "excessive". Even though oil is a lubricant, too much (way too much) can cause pressure build up. A little snow in the muzzle can cause pressure build ups too, even though it is not heavy or packed tightly. My brother for some unknown reason stuck a 12 gauge into a snow bank then pointed it up and pulled the trigger. The snow was not packed in very tight, it was fluffy, about 3" of it, I am guessing. There was a noticeable bulge right behind where the snow plug started. He told Dad that he fell and did not notice the snow in the bore, I know better. I use Kroil in my bores. After a through cleaning, I run 1 wet patch followed by 1 dry one. It still leaves a little oil in the bore, but not so much that it runs back into the action or that would cause pressure build ups. It is not even enough to cause a POI change, just a very light coat. I have been using Kroil in my bores for some time and either Rem Oil or Break Free on the outside, if there is a better alternative, I would like to know. I really have not had a problem, but always looking for some thing better.
