Yup. Big difference. Those 370's may just be about as big/long as you can get through that particular barrel with any really repeatable accuracy. Paper patching is something I got into a good many years ago but didn't really stay with it long enough to consider myself well educated in the art. And an art it is from what little I experienced. Dad got into it a lot deeper than I ever did with a couple of his old sharps paper cartridge rifles. Both of those went to Mr. Simmons since none of us had any real experience with them other than the basics and he and the old man always fiddled around with them.