only thing i worry about with the 870 full is bulging the barrel with bigger shot. i have used 4's ok but would like to try 2's and 3's. this old 870 i got from a dear friend since passed and don't want to harm it.
Ah yes, I forget that lots of hunters use steel shot- full choke bulging probably is a consideration with this stuff. If you use bismuth or other soft non-lead shot then I stay with the recommendation for just using you 870.
