I set FL centerfire dies to size the case to fit that rifles chamber.

Don't FL size with the die right down to the shell holder.

Set the die, to start, with it backed off of the shell holder and FL a case. Try that empty case in your rifles chamber. When you can feel the bolt close on the case then lock the die ring there.

Also reach inside of every case with a feeler rod to detect incipient head separations.

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