i stick with the same load for the whole year, kent 3.5" 1 3/8 oz of #2 @1550fps out of a LM choke in a SBE.

keep the same chokes in your O/U, and shoot some high velocity steel. kent, win supreme, estate are all good brands. go with a lighter payload and higher velocity over a heavier payload and slower velocity.

if you go with non steel non tox non inexpensive; kent matrix and hevi shot are quite popular. i think you' ll want a mod and full if you shoot the matrix.