Re: Do I need to open up Lapua flash holes?
Having been there and done that with the bloody tee shirt hanging in the closet, I will say leave Lapua flash holes alone. I have tried it all and come to the conclusion Lapua knows what it is doing.
They really are optimum size for the brass they are in for consistent ignition and low ES and SD.
Just check and make sure that they all are open. Sometimes one will slip thru.