i personally had a very similar set-up mine was the survivor with the 24 in turkey barrel, i tried adding sand, gel packs ,pennies you name it...it was the most brutal thing i ever shot in my life!!! the way the survivor stock shoulders puts all the recoil "in" your shoulder...ouch, i would go with 2 3/4 loads or three in, not sure if the 28 in barrel will go 3 1/2 or not ,good luck to you :cry:
Bill