Additional data incoming.  Try to answer previous questions.

I checked gauge diameters and found- go =.552, NO-GO =.551 and FIELD =.544.
Gauges are flat, without bevel (unlike ammo).
None of the gauges get stuck in chamber
No excessive wear indicated on bolt.
I believe the sides of the rims of gauges are hitting the interior bolt flange on the go and no-go gauges as they will "rock" when placed against the bolt face (also may be too large as indicated by the measurements).
I did not have aluminum cans to use as shims so I used blue painter's tape which measures at .004.  I applied it to the interior of the bolt face and found that the NOS bolt would not close on the field gauge nor the go or no-go.  The old bolt would not close on the field or no-go gauges but would close on the go gauge.  What is this telling me?  The field gauge measured at .685 and add the thickness of the tape of .004, neither bolt would close on a thickness of .689.  Can I extrapolate that this would be ok?  If I had a field gauge that measured .690-.700 and the bolt would not close, would that be ok?

I am going to ask several dumb questions and if they have been asked already, I apologize.

What led to you checking the headspace? Did you fire the rifle and discover issues? If you fired the rifle, what did fired cases look like? Does the old bolt close ok on a factory round? Does the new bolt close ok on a factory round.

Thanks in advance, I look forward to the answers.

Can anyone recommend a Krag specialist in the Stafford, Va. area?

Here's my 2 cents once again.

I believe it might be a gauge issue...otherwise, carry-on and good luck with your reputable gunsmith search.

Below are photos of the NOS bolt with the Clymer GO gauge and .30-40 round.

IMHO: The GO gauge should be even (or close to it) with the bolt face rim.  This one seems a wee bit excessive...even after seating the gauge by tapping it with a rubber mallet.

Mark_Daiute wrote on Sep 29^th, 2019 at 9:32pm:


Yes, both bolts chamber rounds without issue.

Thanks Mark D. and Local Boy for your clear/ information gathering questions.

Local Boy - I took pictures similar to yours. My 'No Name/Anonymous' Field Gauge sits square on a bolt face without binding or rocking. There is generous clearance between the 'rim-edge' of the gauge and the bolt-head flange.

A cartridge case 'fits' in an identical manner.

The cartridge case rim is about .064" thick. The 'Field' Head-Space gauge has a rim about .073" thick.

These two bolts close easily on a factory case, but not, on the Field Gauge. (Which is as it should be).

FWIW - (I assume ChuckW has been using his Gauges with a stripped bolt. Trying to do so with an assembled bolt adds mechanical functions that interfere with being able to feel contact and resistance. Also, the firing-pin tip would make contact with some styles & makes of head-space gauges, making valid testing impossible).

The advantage of using aluminum drink cans is after you have cut the 2 ends off the can with a pocket knife you could probably cut the disks out with a pair of reasonably sharp household scissors.

One thing with measuring the shoulder diameter of the gauges with calipers, even digital ones, they can lie to you. I would be more inclined to go by the numbers printed on the gauge or storage container.

butlersrangers wrote on Sep 30^th, 2019 at 4:19pm:

Barely can keep up with stuff as it is, if you can spare a gauge for a few days, you could always send it to me and I can verify the number is as advertised with that gauge I checked the cases with.  see reply#18