Double D,

Thanks for calling my attention to Michael Petrov's article. I have subscribed to PS for many years and must have read it when it first came out, but didn't really register on the implications. After reading the article, I measured some fired cases from my .400 Whelen and was relieved to find that the shoulders measured roughtly .453", not .458", but certainly enough to reliably headspace on. My rifle was chambered using a reamer made by the late "Red" Eliot, who would certainly have used the correct dimensions when grinding his reamer.

My experience with headspace problems in the .400 Whelen is confined to the use of reduced loads and cast bullets. There is something about the reduced loads which seems to create excessive headspace in the cartridges, so I have avoided using them. I don't know if the firing pin blow pushes the case slightly forward in the chamber and then the low pressure is insufficient to push the base of the cartridge firmly against the face of the bolt, in effect moving the shoulder to the rear, but whatever it is, cases previously fired with reduced loads tend to produce misfires, due to insufficient primer indentation. Not a dangerous situation in itself, but annoying and possibly life threatening if it happens in the face of something trying to take a bite out of you.