Modeling a Revolver's Cylinder?

Pardon me, as I have a question as I’ve always been perplexed, but; How do you model the Cylinder of the Revolver? I’m bewildered as to how they make it so that there is a space for the model of the bullets to fit through… It always winds up funny for me, that is unless they just use textures and such to fool the player into thinking there is bullets. Thanks for any help!

well, textures are an option, but can’t you just simulate the bullets by making cylinders through your model, then extracting them?

You mean like expanding the surface/face of the sides of the bullets? What do you mean? I apologize for my novice understanding, I’m trying to correct that.