That's a great pic, thanks for sharing.

Got to love once fired mil 50bmg range gun brass, since the barrel chambers on the barrel get worn out and the gun still run.
Hence praise virgin pull down cases/brand new brass when you can find it.


As for if you can only find once fired brass (hopefully unprocessed), then run them through a .604" push throw sizer to begin with after cleaning.  
If a cases have been budge way out just above the case web from shot through a loose chamber 50 bmg/head space not set correctly, you will feel in in the press handle to know that that case should be trashed from the start instead.