I use to shoot F's before I went out and patterned them with my gun. After that I quit using them because the pattern spread out a little more than I like a 40 yards (only 3 pellets hit the gooses silhouette) Instead of shooting F's for pseudo high flying geese I use T's they seem to pattern better for me (anywhere from 6-15 pellets in the same sized silhouette at the same distance)and it kills geese very very very very well.

Wait, wait, ready PLUG EM!!!!!