Those Kent shells at 1 1/4 1400 fps will produce 34% more recoil than a 1 1/4 ounce load launched at 1100.

1400 fps is what the box says. I was just clarifying as I had never stated the load.

Sorry I did not see the MV in the thread title, 34% more recoil than a 1100 fps load all things being equal.

I have enjoyed and found light loads very effective for many years. The old high brass 12ga lead load was 3 3/4 dram 1 1/4 ounce at 1330 fps. I don't care to shoot that anymore due to what I think is excessive recoil. The low brass 3 1/4 dram 1 1/4 ounce at 1220 fps was a better factory loading.

I reload and I try to keep my MV between 1100 to 1175 no matter the weight of the payload because it is pleasant to shoot and works great. I don't think loads with MV over 1200 fps offer any increase in effectiveness, only more wear and tear on gun and shoulder.

Turn-of-the-century Live Bird and Inanimate Target shooters used some boomer loads.

January 2 1897
Charles Grimm defeats Doc Carver in Chicago for the “Cast Iron Metal”.
Grimm used a 12-bore L.C. Smith gun, 7 3/4 pounds, 3 3/4 drams “Schultze”, 1 1/4 ounce No. 7 shot, in U.M.C. Trap shell.
Carver used a 12-bore Cashmore gun, 8 pounds weight, 4 drams of Carver powder, 1 1/4 No. 7 shot, in U.M.C. Trap shell.

The standard Live Bird load c. 1900 was 1 1/4 oz. 3 1/2 Dr. Eq. (1275 fps) BULK Smokeless with pressures about 11,750 psi; 1 1/4 oz. 3 1/2 Dr. Eq. DENSE Smokeless was about 12,600 psi.
The modern SAAMI 12g maximum 2 3/4" and 3" pressure is 11,500 psi

Competition guns were limited to 8# (not including recoil 'boot' or hand guard) and recoil with those loads would be about 27 ft/lbs.

Same as Craig, I regularly shoot the 1-3/8 ounce TM load in Super-Foxes and Winchester 21 Duck guns. Actually the later Supers were made after introduction of the 3-inch 1-5/8 ounce progressive load @ 1315 fps. I'll also shoot the Kent TM 3-inch 1-1/2 ounce load in factory chambered 3-inch Supers when conditions warrant use of the heaviest soft/non-tox shells. Same with the 21 Ducks and my Model 12 Heavy Duck pump gun.

I agree with you Pete, in my NH 10ga I shoot 1 1/4 oz ITX at approx. 1100 fps. It seems to as good or better than my friends 3 1/2 , 1600 fps steel in ther auto loaders on geese. Carvel

What is the "point of duck" velocity of a 1200 fps load compared to a 1450 fps load?

An African duck or a European duck?

Bill I am either missing your point or not understanding the question.