On the total opposite side of the spectrum, if you want the absolutely worst gun/most recoil to shoot, try a DoubleTap 45. I managed 2 rounds out of it.
DoubleTap Defense - Creators of DoubleTap?
I read through the ammo requirements. Be easier just to tell people don't shoot anything in this gun. Either that or ship a 50 round box of ammo with every double tap purchase. 50 rounds should be a lifetime supply.