"Jesse" is the usual masculine spelling. "Jessie" is the usual feminine spelling.
Now back to your statement; in the normal firing, cycling of the auto-loading pistol is the same as what you describe as "slingshotting" when you let go of the slide to load the round in the chamber.
It baffles me why you would think that is not the proper way.
You are correct in that the breech end of the barrel is bigger to accommodate the bullet casing, plus allow the bullet to enter at angle from the magazine. But when the bullet is properly sitting in the chamber, the bullet sits into the lands and grooves in the barrel. On some pistols, if you ride the slide when you rack a round into the chamber, you will notice the slide is not fully in the forward position. This is because you didn't allow the energy of the spring to fully seat the bullet into the lands and grooves.
Now that I explained the mechanics of the process, please enlighten me why that is wrong. And who told you this?
Beware the Fury of a patient man.