I live about 40 minutes from their shop. I've had them open chokes on 2 vintage guns. I asked for 006/014 one and 010/020 on the other. When I got home and checked them with my Skeets gauges they were dead on. They chuck the bbls up in a lathe to do the work so the alignment should be good. They are big into sporting clays. They do not work on 410's.