Headspace guages and safety

[bunkysdad]

I have a Enfield No 1 Mk3 and the first ammo that I fired in it was the POF(Pakistani Ordinance Factory) and it didn't do well. Click-bang ever time. I have always wondered if I had a unsafe headspace condition. It passed the field guage test so well that I feel sure it would also pass a no-go test. It can be useful to use the headspace tool for diagnosing certain conditions.
I also have never seen a problem that was actually proven to be the result of improper headspace, however. Something that we have not really discussed unless I missed it is the adverse effects of poor headspace and accuracy. I would think that a properly headspaced firearm would be more accurate, assuming the other areas of the gun were in specs, such as firing pin depth, rifling, chamber condition, muzzle crown, etc.....
Anyway, I want to vouch for the fact that this small coin size tool is first rate quality, and literally takes a couple of minutes max to check and know that the headspace is correct. A car can run ok for awhile if 2 cylinders have low compression, but would you rather drive it that way, or know that the engine is in great shape?

[Izhevsk762]

POF ammo is known as being the "click-bang" type stuff, it's not just you BD.

[Izhevsk762]

This rifle didn't necessarily blow up because of a headspace issue but the poster isn't sure. I know one thing any extra steps you can take to help prevent a failure is a good thing. Whether or not it's ever been documented that a Mosin has blown up I wouldn't want to be the one eveyone posts about it happening too.

http://www.thetruthaboutguns.com/2011/0 ... t-blew-up/

That one had a pre-existing crack in the receiver, it was a manufacturing flaw, not a headspace issue.

[WeldonHunter]

This rifle didn't necessarily blow up because of a headspace issue but the poster isn't sure. I know one thing any extra steps you can take to help prevent a failure is a good thing. Whether or not it's ever been documented that a Mosin has blown up I wouldn't want to be the one eveyone posts about it happening too.

http://www.thetruthaboutguns.com/2011/0 ... t-blew-up/

That one had a pre-existing crack in the receiver, it was a manufacturing flaw, not a headspace issue.

"not a headspace issue" Yeah I said that in the first sentence and noone's really sure why this rifle did this if I remember correctly. I posted this more to show these can have major failures no matter what caused it. I believe the poster stated though he did check headspace and it passed this still happened and I've seen more than one response to this post saying they've shot many or even hundreds of rounds without checking headspace and had no problems. The point is headspace checking is only a step towards safe shooting but anything is possible. Inexperienced shooters that come here looking for advice might see this and think checking headspace is not necessary.

[Izhevsk762]

Yeah, I'd agree headspace should be checked. That being said, I've only ever heard of two M/N receivers failing, the one you posted, and one other that was intentionally exploded. I think it speaks to the general ruggedness of the design when M/Ns have been in this country since 1915, and (including bannermann conversions) I've only been able to find two failures. I'd imagine the majority of M/Ns are not bought by collectors like us, most get bought by people looking for a cheap shooter. I doubt checking headspace is high up on their priority list. I'm surprised we don't see more headspace problems over the years.

[WeldonHunter]

Yeah, I'd agree headspace should be checked. That being said, I've only ever heard of two M/N receivers failing, the one you posted, and one other that was intentionally exploded. I think it speaks to the general ruggedness of the design when M/Ns have been in this country since 1915, and (including bannermann conversions) I've only been able to find two failures. I'd imagine the majority of M/Ns are not bought by collectors like us, most get bought by people looking for a cheap shooter. I doubt checking headspace is high up on their priority list. I'm surprised we don't see more headspace problems over the years.

Dead men tell no tails.

<------------- I'm not trying to be this guy either. Just trying to stress safety to novice shooters.

[Izhevsk762]

Dead men tell no tails.

<------------- I'm not trying to be this guy either. Just trying to stress safety to novice shooters.

Yeah, that's true

But you know how tales of "unsafe" guns spread...

[tjtM38]

I learned a lot about excessive headspace by watching this video. Having said that, this test is NOT being conducted with a Mosin Nagant. The problem, as I see it with the MN is that there is no place for the gas and or seperated parts of the cartridge to go but rearward. I think these guys, experienced gunsmiths or not, were absolutely insane to conduct this test in the manner they did. DO NOT TRY THIS AT THE RANGE!!

http://www.americangunsmith.com/vidlesson/?id=37d

[bunkysdad]

Dropkick, and anyone else who may be interested, I snapped a few pics of the field guage and how it fits easily on the bolt head without removing the extractor. This is a very nice feature that makes a headspace check about a one minute process.

I placed the bolt in a soft jjawed vise so you can see where the tool fits.

The tool is a very precision ground coin like disc notched to clear the extractor.

With rifle held vertically place the disc into the bolt head space

As the bolt will not close when applying gentle pressure the rifle passes the field guage test. Test would be the same with a tighter tolerance no-go guage. No-go or field is a preference thing that one must decide for themself, but I am good with a field guage test.
As has been seen, this has been kind of a debatable topic but was never my intention. I am a ASE master auto tech, like Mike(weldonhunter), and we tend to like the technical aspect more than some, and I was surprised to see some of the videos and testimonies of others who have had no real problems firing weapons with excess headspace. I am relieved however to se that if there is a problem perhaps the threat is less likely, but I still would rather err on the side of caution.

[MN Fan]

Nice write up Russell!

[tjtM38]

It looks like an easy task. I had no idea what the gauge looked like. It is already set up to fit the bolt head without extractor removal. I assumed it was like other headspace gauges I had seen that actually went into the chamber and required removal of the extractor. I plan on buying a full set of Okie gauges and start with a M91/30 that I just purchased a couple of weeks ago and has not been fired. Thanks for posting.

[desdem12]

[WeldonHunter]

Thanks Russell, there's a reason we like pictures around here and it's because a picture is worth a thousand words.

[Darryl]

We have no idea if the headspace was checked during the refurbish process or not. They have no idea what they did in that process, the Russian don't talk about that. It is all guess and conjecture. So don't assume it is good.

Just because yours didn't have problems, does not make anyone else and expert in this field. Nor does it mean that every other Mosin will act the same as yours did. And it certainly doesn't give anyone the right to say a headspace gauge is a waste of money. Most of us don't have enough experience in this area to be an "expert". I'll admit it and I'll bet I have a few more rifles than most.

It is always better to know if your rifle has a headspace problem or not. Then you can fix it fairly easy. And it is so easy to do. I headspace check every Military Surplus rifle I own as soon as I get it. Don't tell people is is a waste of money or time to get a headspace gauge, because that is reckless.



Get a headspace gauge for your rifle (or borrow one or have it checked by a gunsmith)...but check it. Make sure it is OK. Don't trust others or what they say. Don't get your nickers in a bunch about it, but take it seriously. To give advice contrary is reckless.

Dolk


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