silly question

[Rustywreck]

Ok, this may be a silly question: I looked at a bullet chart for a 243. The bullet ranged from a short 58gr to a tall 115gr. Since the case is only so big and the chamber is only so big how do these things fit? Some of the bullets are twice the length of others.
How does this work? Do the smaller bullet have to jump a long way to reach the barrel?
See I told you this was a silly question; unfortunately I don't know the answer.