I have a question that has been stumping me for some time now so I figured it was time to put the question out. On the .44 Mag Winchester cases I load they have a constriction in the middle of the case that slowly starts to disappear as the cases get resized. My suspicion was that this was there to extend case life but then I noticed I had a batch of .22LR with the same band on the case. What is the purpose of this band and does it mean anything if I have brass that has been sized so many times that the band is gone?