Two possibilities, if it kicks the snot out of you.
It doesn't fit you, or you use heavy loads.
I shoot 7/8 ounce target loads at 1150 roughly, and 1 ounce at 1200 for hunting.
My 20 gauge AyA and my Beretta 687 are 5 pounds 15 ounces. I have no problem with 100 rounds of target loads at Sporting Clays. I do have a pad for Clays.