I like my 223 FL X Die. Trim once and rock n roll on the Dillon. Primer pockets are the failure point, the very nature of the X die eliminating trimming eliminates case head separations. I'm not sure you understand what they do.
Frank White chamber, Krieger barrel on my match AR.
Phillip McGregor (OFC)
"I am neither a fire arms nor a ballistics expert, but I was a combat infantry officer in the Great War, and I absolutely know that the bullet from an infantry rifle has to be able to shoot through things." General Douglas MacArthur