Sabine Pearlman has a collection of photos of cross-sections of different cartridges. That’s cartridge not bullet. A bullet is the projectile — the bit that leaves the gun, while the cartridge is everything put together (bullet, gunpowder, primer, case, etc.). If you want to see more then let Google be your guide.
While we’re talking about these things, let’s quickly dispel a little 80s Hollywood myth: the teflon-coated bullet. The myth has it that coating bullets in teflon should turn a normal bullet into an armor-piercing bullet. The reality is to pierce armor a bullet needs to be made of a very hard material and move at a very high velocity. Teflon does play a role in this, but not the way it’s portrayed in movies. The harder bullets induce more wear on gun barrels. A coating of teflon helps reduce that wear. Thus many armor-piercing bullets come wrapped in a bit of teflon. In the early 80s the news media focused on the teflon, misrepresenting its role in the penetration capabilities of these bullets. A few action movies later and the myth was firmly set into movie culture.