What is the gun part name where you pull the round part out and it spins and you refill with billets?
That is part of a 'revolver'. That particular part is the Cylinder.
On a revolver? The cylinder. I think.
Chamber or cylinder I think.
cylinder ,on a auto. magazine
I'm not sure what part you're talking about, please retype your question.And I don't think you put "billets" in a gun.(a cylinder)
Slot or cylinder.