I have, what I believe, is tool marks. It looks like rings inside my barrel. I take 4/0 steel wool on a wooden dowel rod and drill soaked with wd-40 every yr to clean the barrel. This has helped my patterns,but the marks are still there. The patterns I get are ok I guess, but I believe they could be better if I could smooth this barrel up. How do I need to do this ?
http://oldgobbler.com/Forum/index.php/topic,182.0.html
Follow the directions above.
I have a newer 870sm in the duck camo that wouldn't pattern well. The barrel had the same tool markings that you described. I sent it to my gunsmith and had it professionally polished. He had to take quite a bit of material out of the barrel to get it right. $30.00 well spent. Not much more than the cost of materials to do it myself and I know it's done right. They use some high-tech polishing tools. Gun will shoot awesome patterns with a number of loads now.
160's in a 10 @ 40 Rem870sm/ Ventilator .655. Win XX 3/2/6's
*no need for HTL turning that kind of pattern with PB.
Send it to Gobbler Guns
Send it to Gobbler Guns