8mm Headspace

[ZimbabweJones]

Bought myself an 8x57 NO Go for these Yugos I picked up and I need a second opinion here.

I know you're supposed to strip the bolt down to just the body but the first time I was obviously excited and I popped it in there and closed the bolt, but it wouldn't close fully. Which I automatically assume is a good thing?

Took the bolts down to nothing but their bodies, put the gauge in and the same result pretty much, both bolts close maybe 1/4 of the way.

Like I said before I put the gauge in with a fully functioning bolt, with the safety in the firing position, the bolt rotates about 1/4 of the way down but its closed enough to still engage the firing pin..




M48BO 8mm gauge in, bolt closed to first point of resistance *My BOs bolt gets a little tangled with the square of the receiver but thats before the gauge prevents anymore movement, so I'm not sure with the accuracy and efficiency of testing her*


screencapture
M48A gauge in, bolt closed to first point of resistance. The bolt and action are pretty solid on this one so I'm not worried.



By just looking here, what do you personally think? Good to go? Needs a little more love? Trash it and buy a real K98?

[Delkal]

Did you remove the extractor? The firing mechanism inside the bolt does not matter.

If the nogo gauge is hung up above the extractor claw you can get a wrong reading. For best results you should remove the extractor but you can try to get the rim of the gauge BEHIND the extractor so its sitting on the bolt face.

Also for an old Mauser you should not be using a nogo gauge. That is what gunsmiths use to fit a new barrel. You should use a field gauge.

[ZimbabweJones]

In the pictures yeah, both extractors are out.

Bolts have nothing in them at all.

[ZimbabweJones]

Also for an old Mauser you should not be using a nogo gauge. That is what gunsmiths use to fit a new barrel. You should use a field gauge.

Thanks for the heads up, probably gonna be my next buy..

[Delkal]

If the extractor (on the outside of the bolt) is removed too then you are good to go.

I am surprised they didn't close on a No go (or be very close to closing). A lot of old military rifles will swallow a nogo (but can still be OK). The field gauge is the one that tells you there is something wrong.

[Delkal]

Thanks for the heads up, probably gonna be my next buy..

If your rifles are OK now with a nogo you have many thousands of rounds to go before you should even think about checking it with a field gauge.

Generally headspacing changes very little with shooting and is only an issue if you are swapping bolts. Your barrel throat will be long gone and you will need to rebarrel before you get in trouble with headspacing.

[ZimbabweJones]

If the extractor (on the outside of the bolt) is removed too then you are good to go.

I am surprised they didn't close on a No go (or be very close to closing). A lot of old military rifles will swallow a nogo (but can still be OK).

Very nice to hear, thank you!! May have lucked out here a bit.

[Ecclectic Collector]

Back when milsups were common and I was buying 8mm Mauser caliber rifles frequently I bought both NoGo and Field gauges. I found out by testing dozens of rifles that the NoGo is helpful to know, especially if you reload; but the Field Gauge is essential. I rarely had a rifle fail on the Field, but it does happen as so many vintage rifles have mismatched bolts.

Rimless cartridges headspace on the shoulder, so an out of spec chamber will cause the case to pull apart if headspace is excessive. A case head seperation is decidedly unpleasent to experience.

[Gunsnwater]

The “GO” gauge can also be thought of as a minimum safe headspace gauge and the rifle's bolt must be able to fully close with it in the chamber. The “NO GO” gauge - is used to make sure a firearm does not have excessive headspace. ... The “FIELD” gauge - is used to check absolute maximum headspace.

Should have all three. Closed is all the way. You know your headspace is not too much. Go will let you know it’s enough and field will let you know not to shoot it.

[Gunsnwater]

PS it’s a gauge, never force it, this is another reason not to play with gauges and assembled bolts. You can not feel the engagement.