GJZ: I can personally testify that the recoil in my less than 6# 1928 20g Trojan with chambers 2 7/16" using factory 2 3/4" Win AA 7/8 oz. target loads was absolutely brutal, and obvious to everyone observing on the skeet field. The perceived recoil with 1 oz. 2 3/4" 1150 fps. 16g loads in my 2 9/16" chambered 6 1/2# LC 16g was clearly less after lengthening the chambers. 1 oz. 2 3/4" target loads in my 2 1/2" chambered No. 2 frame 12g Trojan weighing 7 3/4# felt no different than 1 oz. 2 1/2" shells.
But my anecdotal data may not apply to other's experience, as I have a terrible flinch and am very recoil sensitive.