i just bought a new 870. i have an IC .660 and a tru glo gobble stopper(not sure of dia.). i cleaned it(not polished). shot win 3.5 hv 6's horrible patterns. shot fed 3.5 2.25 oz 5's(with tru glo only) better than the 6's but still pretty bad.
so is anyone using either of these chokes out of a rem 870? what load are you shooting and numbers?
i do have access to get old feds(before fc wad), and old remingtons.
Grab a Ventilator choke and some of those old pre FC federal shells and try those Win XX's again.