Just at a quick glance in an old Alliant handloaders guide I find a 12ga 2 3/4" load giving 1 oz of shot 1330 fps velocity @ a pressure of 9,500 PSI.
From the same hull but different powder, wad & primer 1 oz of shot is given 1200 Fps @ a pressure of 10,600 PSI. Thus 80% of the shot weight is given 90% of the velocity at an 11.5% increase in pressure. The heavier load in spite of its lower pressure will give you more recoil & put more force into the stock.
It is somewhat debatable as to just which parts of the gun the lighter load with higher pressure will actually be harder on.

Miller/TN
I Didn't Say Everything I Said, Yogi Berra