Stick with the F.. I have seen the so called expert and every year I have to play clean up as there little pellets that don't retain velocity. The only way I use any shell is to make sure it is over 1375fps. So many time I cheapies useing the slow discount shells..Yep they save a buck and have somthing to talk about after they bounce pellets off birds...This year we shot 873 honkers and most with High velocity and huge pellets.. If you are useing large pellets then use a open choke. I guess most aint old enough to remember the old 00buck days with smooth bore and rifled sights dead birds way out. Good luck and stick with it.. I have seen more than enough dead honkers to prove the point each year...MBK rules