Mike Yardley is one the UK’s leading shooting authorities and he shares a lot about shotguns and shooting on his website Positive Shooting. I just read though Dealing with Recoiland I recommend checking it out.
“Are you affected by recoil? Many shooting men and women are. There is no need to suffer. Let’s consider what might be done about it. First, a bit of physics. As you may remember from school days, to every action there is an equal and opposite reaction (Newton’s Third Law). Recoil is the motion of a gun in the opposite direction to its projectile. Various factors need to be considered when thinking about the physics of recoil: muzzle velocity, gun weight, projectile weight…”