.002” Past the No Go Gauge!

[deltaenterprizes]

Put the prechambered barrel on a Yogo Mauser that I am building and I could not chamber a dummy round or either the go or no go gauge!😡
I removed the barrel and used the reamer to cut the chamber a little deeper by hand and when I checked it was .002” past the No Go gauge!😡
I did set the barrel back.002” but was it really necessary?

Would you have set it back or let it go like that?

[LAGS]

Do you have a Field Guage ?
That would be your Max headspace .
But it should be easy enough to set back the barrel.
I always try to set my Headspace Snug on the Go Guage.
But I handload mostly , and do not intend to hunt Dangerous game or use it in Dirty Field conditions

[PTCSmith]

A Yugo Mauser (M48 or 24/47) calls for an extractor cut. I also add the safety breech that was part of the original design. Failure to make the extractor cut may make the bolt impossible to close.

I personally would not chamber a new barrel to a field gauge.

[TurnipEaterDown]

Short, easy answer is excess headspace is wrong.

But the world isn't always T/F, B/W, and you can decide after considering what headspace is, what it does, and how risk of excess headspace differs on different headspacing types. Also, end use of the gun matters, in some circumstances.

Excess headspace can cause a dangerous condition, but does not necessarily do that with every cartridge type.

I don't see that you state what cartridge chambering you cut.

I would Never run a belted magnum with excess headspace.
This type headspaces off the belt which has an abrupt (90°, ~ 0.010") transition to the body. A user can experience a belt recess blow out if the headspace is long and a false headspacing is created by utilizing the shoulder to control cartridge position. Pushing the shoulder forward by firing, and leaving it there when sizing (thus creating the false, or secondary, headspace off the shoulder) will create an unsupported condition in front of the belt where the cartridge can rupture. The belt is fairly far up the case (~0.220) and if the camber is deep here, this can get you past the solid head depending on case design.

Rimmed cartridges headspace off the rim, and basically if headspace is long then the circumferential groove to receive the rim is too deep (out of spec) for the rim thickness.
Here, the (Modern!) case IS solid ahead of the rim for far enough that it will not blow out.
Some people say that maybe you run into too little firing pin protrusion to set off the primer, but I think that is unlikely at 0.002 excess. What IS likely to happen is that if you do NOT set up your dies to (falsely) headspace the cartridge off the shoulder, you will repeatedly stretch the brass at every firing and can get a separation eventually of the case body.
This is the difference from belted to rimmed. Functionally the belt is a tiny forward placed rim, but whereas I would never headspace a belted cartridge off the shoulder, I would actually in some instances recommend headspacing a rimmed cartridge off the shoulder. With a modern solid case head you should not experience a blow out risk into a rim cut.
Never try this w/ old balloon head brass (frankly, I wouldn't use balloon head brass, period) as the balloon head is just that: like a RF, it does not have a solid portion ahead of the rim at all.
You are unlikely to have a rimmed cartridge in a Yugo Mauser, but it can be done.

Rimless/beltless bottle neck cartridge? This has the least risk with a couple thousandths excess headspace, IF it is managed correctly.
Simply stretch the case Neck UP in diameter to something 0.030 or so Bigger that the actual chambering, and then set up your sizing die such that another pass with the correct die forms a false shoulder just a bit forward of where it is on your brass you started with and the sized case chambers with a bolt close that has a very Slight resistance to set the shoulder of the case firmly against the chamber shoulder. Lock the die, and always size using that die & shellholder. Functionally you have then created a wildcat that is perfectly safe, but is dimensioned ever so slightly different than it's (probably) commercial cousin.
This is where end use comes in: If you chamber mark the barrel with the std cartridge ID, it is technically unsafe. So, selling it presents an unknown risk to the buyer. If it is yours and you know how to use it, it will be OK. I suppose you could mark it "+002 HS" on the chamber stamp if you were a nitpicker, but no one would be expected to know what that means, as no one does that.

BTW: No one better have the expectation that LOTS of old military rifles weren't produced just this way: long headspace.
Production needs under duress, etc. make it happen. Indeed, I seem to remember some turn of last century military cartridge Purposefully produced "short" of what we would consider commercial HS by a considerable margin, due to the fact that if you are crawling around on the earth, carrying hastily produced ammunition, poking it in a dirty / poorly cut chamber, and you absolutely must have it go in and go "bang" when pointed at the enemy, then a loose fit is your friend. Rarely caused a problem as infantry aren't reloaders, and loose fit doesn't mean non-functional fit through grossly excess dimensional mismatch.

[waksupi]

As a hand loader, I don't consider excess head space a problem. Load the rounds to contact the rifling, fire form to the chamber, and keep that lot of cases for that rifle. That is an advantage to hand loading. If we were stuck with factory ammo, it could be an issue.

[M-Tecs]

Put the prechambered barrel on a Yogo Mauser that I am building and I could not chamber a dummy round or either the go or no go gauge!��
I removed the barrel and used the reamer to cut the chamber a little deeper by hand and when I checked it was .002” past the No Go gauge!��
I did set the barrel back.002” but was it really necessary?

Would you have set it back or let it go like that?

No it was not necessary if you use the method that waksupi suggested. Personally I would have set the barrel back .007" or 008" not .002" since I prefer to set everything to minimum over the go gauge not just under the No Go.

https://mansonreamers.files.wordpres...tolerances.pdf

https://www.forsterproducts.com/pdf/...at82_38-42.pdf

[jdsingleshot]

Some folks didn't read your OP carefully, but yes, since you had the means, then by all means set the barrel back, as you did.

[Winger Ed.]

I'd take the time & effort to do it right.

It's not like 'you'll shoot your eye out kid',,,, but it would always bug me that it wasn't done to specs.

[deltaenterprizes]

I'd take the time & effort to do it right.

It's not like 'you'll shoot your eye out kid',,,, but it would always bug me that it wasn't done to specs.

We think alike! I could not let it go knowing it was not right.
It did not take long to do it and I feel better now knowing it was done right!

[John Taylor]

Head space is not as critical on lower pressure cartridges but it always a good idea to set them up close. I have had1894 Winchesters in 30-30 come in with .025" headspace and the customer was still using it for hunting, all that happened was the primer was backing out. Someplace between the pressure of the 30-30 (42,000 psi) and the 7x57 ( about 49,000)and up, the brass will stretch to fill the chamber. When this happen you can usually see a line about 1/4" to 3/8" in front of the base, depending on the cartridge. This usually where the cartridge will separate from the base, especially if the case is full length resized every time it is reloaded.

[MostlyLeverGuns]

Since you have the means, set the headspace correctly. I have a couple Savage 99 358's, the ones made in the 80's(?), both are factory headspaced the same, very long. Some available factory cartridges and some new brass (Winchester) cause misfires in these rifles. A combination of a short factory cartridge and a long chamber can cause a misfire, some folks worry about extremes like KABooms, but mostly excessively short brass life and sometimes an incipient head separation occurs. Old or junk brass can separate, how the action handles gas determines whether results are harmful. Mauser 98's handle gas very well, Winchester 70's, not so much. I would go for the GO guage and stop there.

[fast ronnie]

I try to set tight on a go gauge.

[2152hq]

You would like it to not close all the way on the NO-GO gauge ,
But it is still 'in spec' if it DOES close all the way on the NO-GO,,,but DOES NOT close entirely on the FIELD gauge.

The first reading just shows a tighter chamber HS than the second reading.
Both are within the 'In Spec' range

[Wolfer]

A long time ago before I had a lathe I built a 270 using a prethreaded short chambered barrel. While finish reaming I cut deeper than I wanted. Bolt would close on a no go with considerable pressure. Having no way to set it back I just shot it. Worked fine. I hold my die up a little and case life has never been an issue.

[Moleman-]

Since you have the means to easily do it, yes I would set it back. I've been in that same situation and always set the barrel back as I like to set it closer to the "GO" gauge.

[LAGS]

When setting Headspace.
The bolt should not close at all on a No Go gauge.
It should stop at about half the rotation.
At that point you do not Force it closed.

[deltaenterprizes]

When setting Headspace.
The bolt should not close at all on a No Go gauge.
It should stop at about half the rotation.
At that point you do not Force it closed.

That is exactly how it is now!

[M-Tecs]

I am having a hard time understanding why anyone would want to set headspace off the No Go gauge? Most factory ammo is .003" to 005" under the SAAMI minimum (Go gauge). The No Go gauge is .006" over the Go gauge so you can have .010 stretch each firing with factory ammo.

I mostly just purchase Go gauges only for chambering. I set headspace to 0.0" to 0.0015 over the Go gauge. For barreling and chambering No Go and field gauges have very limited usefulness. I do have incremental gauge .001" step sets in .223, 308 and 30/06 to check for issues on existing firearms.

When I set my dies for shoulder bump .003" is the max and between .001" & .002" is the goal.

For belted cases I special order headspace gauges so they headspace off of the shoulder not the belt.

[ulav8r]

A long time ago before I had a lathe I built a 270 using a prethreaded short chambered barrel. While finish reaming I cut deeper than I wanted. Bolt would close on a no go with considerable pressure. Having no way to set it back I just shot it. Worked fine. I hold my die up a little and case life has never been an issue.

You should NEVER use considerable when using a headspace case, it can damage the gauge and give false indications. Use light pressure on the bolt handle, use a stripped bolt so there is no spring pressure to interfere with the measurement.