felt
About "soft" shooting guns....
If I shoot the same ammo out of three different guns of the same weight and barrel length...assuming the same velocity, "free" recoil will be the same.
There are other elements of gun design that may/will "soften" the "felt" recoil: the materials used in construction of the gun, the location of the boreline of the barrel in relation to the hand and bones of the forearm, the design of the grip -width, length, depth, angle (ergonomics) and materials used in for the grip, the compression value of the recoil spring(s) (if a semi-auto).
I have a Ruger SBH in .44 Magnum. The factory grips allowed the gun to move in my hand more than I like. Recoil was not unmanageable but not fun either. Change to a wider, softer grip...a bigger grip overall...and the gun became less of a task to shoot..."softer" if you will.
Pete