It does look like you are clearing some grease from the barrel, which is a good thing. There will be some resistance but, if it is too much, use less cleaning rag. I would not use a paper towel, though. Use something softer to reduce the risk of scratching the barrel; I use strips of J-Cloth with Isopropyl alcohol. Make sure you do not damage the hop rubber. It is better to take the barrel out of the gun to do it, if possible; that enables you to get a good look down the barrel to make sure it is clean.