Note that target 20s are not light. Field 20s tend to be.
See http://skbshotguns.com/GC7-Series/Clay/GC7-Clay.php
A 7.5 lb. 20 Gauge with regular 7/8 oz. loads at 1200 and a pad is not at all bad.
Red Labels are on the heavy side so that helps with recoil, too.Love my Ruger Red Labels. Try a recoil reducing device. (mercury, spring, pad, many choices)
Take that same 7/8 oz load and shoot it in an 8-1/2# 12 gauge and see how much softer it is..
Go to a large skeet, sporting or trap shoot and look around. You will see many shooters with recoil reducers on the stock.