Sanity Check (.300 Norma Rebarrel)

[LB7DMAXX]

Decided to ditch the old .338 Lapua barrel after 50 rounds (110 HS Precision) and go to .300 Norma Mag, I finally got my barrel in the other day. Today I pulled the old barrel off cleaned the action, pulled the extractor off the bolt, & cleaned the brand new barrel. I screwed the barrel in til it contacted the GO Gauge, backed it off, and started checking the bolt movement. Now here’s where the problems start... I find the sweet spot, snug up the barrel nut (not torqued) and replace the GO with the NO GO Gauge... The bolt closes on it... No big deal, I put the Go gauge back in, loose up the barrel nut and screw the barrel in every so slightly... Same Result, the Bolt closes on the NO GO... I repeat this process all the way to the point the bolt is uncomfortably heavy and still it closes on the No GO... I pulled everything back apart, re-checked/cleaned everything and still the same result... Now I have done probably 10-15 re-barrels on everything from .223 thru .338 Lapua and I have never had these issues... I did email the barrel Manufacturer, but today being Friday I don’t expect a response until early next week.. Obviously something is not right, but I wanted to post it up here just in case someone has any insights on something I may have overlooked.

[RustyShackle]

Do you have a way to check the headspace gauges? And who made them?

[LB7DMAXX]

They are made by PTG
I did check the difference in the two gauges (.003”)

[RustyShackle]

Can you measure the case protrusion from the bbl and the depth of the bolt face?

[LB7DMAXX]

I can... I did just discover something, if you stick a Go Gauge in the barrel (barrel not installed and facing downward)and place the bolt over the gauge (as it would be if the barrel was installed), the bolt is hitting the barrel before it has been fully seated on the gauge (Both GO&NO GO). My guess is the barrel was reamed too deep... Though I am not a gunsmith so maybe that assumption is off..

[RustyShackle]

Bolt face might be too deep. measure that and post back with your findings

[LB7DMAXX]

Will do

[LB7DMAXX]

Bolt depth- .137”
protrusion of Go Gauge-.129”

[RustyShackle]

I believe you will need to change your bolt head, I think the lapua has a different case protrusion spec. Something like 0.145? Or cut some of that bbl face.