John- I am not a AH Fox expert- I have a 20 Sterlingworth with DT, mine is a later series made in Utica NY- it has 2.75" long chambers, although I shoot 2.5" RST loads in it-- If you have an early Phila. mfg. gun it is possible that it may have 2.5" and NOT 2.75" long chambers- if so, that may be one reason for the seemingly excessive recoil-
A minor point, more akin to the precision rifle shooting area, but how much of your finger pad contacts the trigger blade may also be part of this situation- and gun fit too-
Chamber length perhaps?
Threaded Mode