The remington turkey choke that came with my 870 measures .690. Paterns weren't anything to write home about so I would recomend using #6 shot for a denser pattern. #5 shot patterns were too loose to shoot past 35 yards, and #6 lead shot carries enough energy to kill a turkey at 40 yards. I know that a lot of guys like the high velocity loads but the pattern like crap in my gun. I have much better patterns with the 2oz loads from either remington or kent.