Pattern master is a great product. If you need Mike See's tele I can get it for you. I took some tactical shotguns to the LETC (advanced law enforcement training camp) and let many le firearms trainers shoot identical guns with and without the tubes with FED h132 tac buck at all ranges. We got one 5 " group at 50 yards. Also had Vang comp too. Many went back and ordered barrels for their depts. I've shot 25s at trap with my 870 deer/slug gun with the pattern master barrel. Ive only shot 23s with Hans'es 18" riot vang comp.