I got my Go and No Go gauges (will be barreling with a bull barrel) in today and thought I'd just try the gauges out being this would be my very first experience with bolt action and head space gauges. I find the bolt won't close on the go gauge; It doesn't close on the No go gauge as expected. I don't have my ammo yet so I can't test the action any further. I'm puzzled by this and I wonder if I'm doing something incorrect. Action is 300 win mag and gauges are Forster Headspace Go and No Go Gage Belted Magnum (.535" Base)