Polishing the feed ramp is NOT the cureall that a lot of people believe.
The feed ramp helps to get the tip of the bullet lined up. If it has tool marks that the nose is filling up, then polish a little to stop it.
What does affect feeding is the magazine and the lips of the magazine (and to some extent, the breech end of the barrel).
As a round comes out of the mag (talking .45ACP now), the nose of the bullet does contact the feed ramp. As the bullet is pushed forward by the slide, the nose of the bullet "jumps" to the top of the chamber of the barrel.
This is a good example of how a 1911 works. You can hide different portions of the animation to see exactly what happens.