Parashooter wrote on Sep 29
th, 2019 at 5:58am:
For a sanity check, measure the maximum rim diameters of your gauges. I suspect you may find the Clymer gauges are larger there than the Forster. If that's the case, it's likely the Clymers are running into something on the breech face that the Forster isn't. Could be crud or corrosion, or maybe someone reamed the face a bit, leaving a "step" that's keeping the gauges from giving a true reading.
If you can find an aluminum beverage can and cut a few shims that fit easily in the bolt face, you can learn how much end-play there actually is with a normal cartridge. Most common drink cans go about .004". You should find one such shim allows the bolt to close easily on the cartridge. Two shims (.008") is still acceptable. Three (.012") isn't great, but unlikely to cause problems. Four shims (.016") indicates a moderately serious problem, though little danger of separation unless you repeatedly FL resize cases when handloading.
(This is likely more practical information than you're getting from the gauges - since it shows how much cartridge stretch you'll encounter when firing your ammunition.)
Parashooter, My mention of rim diameters in question #1 was the one I thought most likely. One other possibility is this is a parts rifle, if the bolt bore threads and chamber are all off center in opposite directions
the heads of the gauges may bind in the bolt end recess.
Also could you clarify the up to .016 clearance tested with shims , which gauge are you suggesting doing this with?
The other questions with possible causes are less likely and typed in no particular order as I was racing a computer reset.
BR's reference to using an experienced Krag gunsmith is good as not all gunsmiths are familiar with Krags.