Quick discussion of felt recoil. To the experts, I’m skipping the details and simplifying.
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I'll probably screw up the actual physics terms here, but it's after 2 am, so forgive me.
Another factor which strongly contributes to felt recoil is the design of the gun itself, with respect to how the reaction force of the gun against the hand is felt with respect to time.
Essentially, the longer the impulse of force is spread out with respect to time, the less the magnitude of the "felt" recoil. This is key to the moving parts of the gun.
As an analogy, consider a steel hammer. If you drop a hammer on your toe from a height of 5 feet, you'll experience a bit of pain (and likely injury), because the energy of the falling hammer will be absorbed in the fractions of an inch in which the hammer is forced to decelerate as it deforms (crushes) your toe.
Yet the same hammer, dropped from the same height, will present less of an "impact" on your toe if something in between works to decelerate the hammer (absorb some of its kinetic energy) before it actually hits your toe. Like a leather work boot. The hammer still hits with the same amount of kinetic energy, but it's being absorbed by the action of your leather boot compressing over a finite amount of distance before it reaches your toe.
Likewise, if you change the nature of the hammer, you can change the felt impact. If you drop a rubber hammer of the same mass from the same height, the result will be different than from the steel hammer. It may still hurt your toe, but you may not break anything, for example.
How the barrel (and when) the barrel and slide move on a pistol thus contributes a great deal to felt recoil.
This is the same principle applied to car design and manufacture. Modern cars, in general, are safer because they're designed to crumple and crush on impact, absorbing some energy and spreading out the time of impact so that by the time the forces reach the people in the car, the resulting magnitude of impact is lower and spread out more.
