I recieved my Green mt. barrel a couple weeks ago. I threaded it, chambered it for 45/70, cut dove tails for sights and shot it 10 times, cleaning it between each shot until there was no more copper in the bore then shot it 10 more times cleaning it between every 2 shots. It just got easier and easier to clean and kept getting smoother . It looks like it's going to be the most accurate rifle I have. The barrel I chose was the Sharps #1 heavy 45 L which is 34" long, (4140). It's the only Rolling Block I've shot except for .22 cal. They sure are a lot of fun.