Last Wednesday I went out and shot about 18 3" shells and noticed a discomfort. Yesterday, shot 12 3 1/2" shells and now my middle finger on my trigger hand is bruised and swollen. Pretty sure it is the trigger guard hitting it.

Any reccomendations on how to keep this from happening? I dont want to get away from the 3 1/2" shells as it seems that is what I am hitting the birds with...1 duck in the freezer, 1 cripple, and 3 coots (2 recovered) hit.