That stuff in the barrel is to protect the bore. I had the same stuff in my Lyman. It took a lot of solvent and patches to clean all that out. Run a boiling soap and water bath through that. The boiling water will melt that packing grease and float it right out of the barrel. Then as it cools you can solvent the bore down and patch it clean. I bet I gave that Trade Rifle three water baths. And I was using Hoppies #9 solvent to get that black packing grease out. But once it was clean that bore in mine looked perfect.