I have fired factory 3" 1 oz loads from a 6 lb 20 gauge as well as handloaded low velocity 1 oz loads from a 16ga which was 2oz under 6lb. I would want to use neither for continuous firing but for spaced out shots in many hunting situations they were not at all uncomfortable.
Over the years I did seem to do some of my best shooting in the hunting field with guns in a 6lb-7lb range. In this weight range the normal 3-1 1/8 loads were quite comfortable & up to 3-1 were no problem. In a 12ga of at least 6 3/4lb I had no problem with the 3 3/4-1 loads.

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