6mm BRX Fire Form Question

[rcw3]

I am working on setting up a 6mm BRX. A question I have is related to fire forming. I have worked with a number of improved type cartridges where the shoulder is blown out and forward, and when you do that the brass typically shortens up a little bit. I assume this is typical with the 6mm BRX as well but I was just wondering if anyone had an idea what the length of the cases were after the fire forming of them?

Robert Whitley