[Unclenick]

AJ,

Go and no-go are something of a judgement call. If I look at the SAMMI drawing for the .308 chamber, it gives a minimum of 1.630" and a maximum of 1.640". But 1.640" is a worst case field length. A set of armorer's gauges I have for .308 say the go is 1.630" and the no-go is 1.634" and the field no-go is 1.637". A set of gauges I got with a reamer from Dave Manson for the 6.5-284 uses a no-go that is only 0.0025" above go (he is really trying to keep that match chamber within tight limits). Those gauge ranges of 0.0025"-.0040" chamber tolerance are reasonable to expect a gunsmith to meet, but factory work doesn't always stay within them.

Anyway, the first question is whether your Stoney Point gauge is meauring accurately or whether you have a bad set of headspace gauges? See if you can borrow an RCBS precision mic and check the gauges and case in that for verification? "0" on the precision mic is 1.630", though it is not a true precision instrument and mine is off about 0.001". Still, if it gives you numbers that are different by more than, say, 0.002", you definitely have a measuring tool issue. You could call Stoney Point about it.

I've had bad headspace gauges before from Forster that were out by up to 0.002". Buy gauges from Dave Manson or another reputable reamer maker. I also suspect your measuring gear because the gauges are showing short of SAMMI numbers and your case is 0.005" below the SAMMI minimum case dimension. I could see a little spring-back, but not that much.

Nick