Im shooting a Remington 870 super mag with a 28" barrel with winchester 3.5" #5 shells and I have a remington superfull choke and Im not getting a reall good pattern out to 40 yds I was wondering if I should go with a #6 shot or go with a new choke tube. I was also wondering what makes a difference with two different choke tubes that have the same constriction. such as a remington super full and the undertaker with a constriction of .665. what will make one better than the other? one more thing is what do you guys suggest for a choke for this gun?