Will mix-matched military surplus rifle explode at you?

[nozama]

I recently picked up a Yugo captured Kar98k. Nothing matches on it, I putted 15 rounds through it and it shoots great. I also have a Mosin that I've fired at least 800 rounds through in my hand, and it has never given me any problems. The Mosin, made in 1932, has all matching parts and is accurate enough to get me through a 12x20 steel plate at 300 yards. It does go loose quite often as I shoot more and more that I have to tighten the screws on the bolt receiver to make sure nothing is waggling. Both rifle close the bolts perfectly.

However, my concerns started with some YouTube videos where I saw people explode themselves with their guns, and I began to worry if that would happen to me one day. I heard some people say that you need to check the headspace of these surplus rifles, especially the mismatched ones. I checked with the gun stores in my area, but none of them work with military surplus rifles. The only one with experience in this area eyeballed it and told me to just have fun with it. He told me that the worst thing that could happen would be a 'no-go.'

I have a deep love for military surplus rifles and enjoy practicing marksmanship with them. They have historical charters that I couldn't pay enough respects on. I'm in my 20s and the last thing I want is putting a grenade in my face. My question is, can these rifles explode? What are some things I need to pay particular attention to in terms of maintenance? Any insights would be valuable.

 

[Muncher 1953]

“beware of free advice”, but here is some, honestly offered:

buy yourself a ‘field’ headspace gage, like this:

Forster Headspace Gage 8 X 57 Mauser Field HG8X57F for sale online | eBay

Find many great new & used options and get the best deals for Forster Headspace Gage 8 X 57 Mauser Field HG8X57F at the best online prices at eBay! Free shipping for many products!

www.ebay.com

from wherever you choose (Graf Brothers, Midsouth shooters supply, brownells, Natchez shooters supply, midway usa, Scheetz, etc)
follow the instructions, but if the bolt will close on a field gage, it’s probably unsafe to fire. what happens with ‘too much head space’ is that the chamber is 10-20 thousandths of an inch too long, (due to wear on the bolt lugs) & the cartridges stretch to fit the chamber, until they burst just forward of the head/extractor groove.( the ‘butt’ of the cartridge is unsupported by the chamber walls) In a rifle not designed as well as a Mauser 98 is, this could result in eye or facial injury to the shooter, even death. But these rifles are old, so don’t tempt fate, even considering the layered ‘fail-safes’ of the design, excess headspace needs to be fixed by a competent, old-time gunsmith, or at least another bolt that does pass. when you look closely at cartridges from a rifle with marginal -excessive headspace, you can see signs of stretching, & if reloading, they’ll seem excessively long. (because they’ve stretched) If you reload, don’t push the limits, if you reload using surplus components, be wary of bullets that haven’t left the barrel after an apparent ‘misfire’.

when I buy a rifle of unknown provenance, I put it in a shooting rest & fire it from 25’ away. if it doesn’t blow up after 2-3 rounds of standard ammo, I figure its OK, but then I’m 70+ YO, so maybe my perspective is different than yours.

Enjoy your ‘new’ rifle!

 

[bnz41john]

Mauser 98 actions are perfectly safe to shoot even with bad headspace. Keep in mind I said mauser 98 actions. Only mauser 98 actions. Which your k98k has. If you are supper concerned you can buy a field headspace Gauge.

Do your own research before you let yourself get worked up over random sh*t you see on the internet. That goes for more then just talking about milsurps.

 

[nozama]

“beware of free advice”, but here is some, honestly offered:

buy yourself a ‘field’ headspace gage, like this:

Forster Headspace Gage 8 X 57 Mauser Field HG8X57F for sale online | eBay

Find many great new & used options and get the best deals for Forster Headspace Gage 8 X 57 Mauser Field HG8X57F at the best online prices at eBay! Free shipping for many products!

www.ebay.com

from wherever you choose (Graf Brothers, Midsouth shooters supply, brownells, Natchez shooters supply, midway usa, Scheetz, etc)
follow the instructions, but if the bolt will close on a field gage, it’s probably unsafe to fire. what happens with ‘too much head space’ is that the chamber is 10-20 thousandths of an inch too long, (due to wear on the bolt lugs) & the cartridges stretch to fit the chamber, until they burst just forward of the head/extractor groove.( the ‘butt’ of the cartridge is unsupported by the chamber walls) In a rifle not designed as well as a Mauser 98 is, this could result in eye or facial injury to the shooter, even death. But these rifles are old, so don’t tempt fate, even considering the layered ‘fail-safes’ of the design, excess headspace needs to be fixed by a competent, old-time gunsmith, or at least another bolt that does pass. when you look closely at cartridges from a rifle with marginal -excessive headspace, you can see signs of stretching, & if reloading, they’ll seem excessively long. (because they’ve stretched) If you reload, don’t push the limits, if you reload using surplus components, be wary of bullets that haven’t left the barrel after an apparent ‘misfire’.

when I buy a rifle of unknown provenance, I put it in a shooting rest & fire it from 25’ away. if it doesn’t blow up after 2-3 rounds of standard ammo, I figure its OK, but then I’m 70+ YO, so maybe my perspective is different than yours.

Enjoy your ‘new’ rifle!

Thank you so much for your detailed input! These are such good advices. I will get myself a pair of gauges just to be safe. I only shoot modern manufactured ammos and thankfully I didn't notice any uneven stretches whatsoever.

 

[Muncher 1953]

field & no go gages are the ones you need, the go gage is only for cutting new chambers.

 

[heavy_mech]

Mauser 98 actions are perfectly safe to shoot even with bad headspace. Keep in mind I said mauser 98 actions. Only mauser 98 actions. Which your k98k has. If you are supper concerned you can buy a field headspace Gauge.

Do your own research before you let yourself get worked up over random sh*t you see on the internet. That goes for more then just talking about milsurps.

100% agree. You'd have to have some unusual/extreme circumstances and I'm still not convinced you'd have a blow up. I think that's more fun show mythology than anything. Carcanos blow up all the time if ya didn't know.

 

[Fal Grunt]

Did you exam how the YouTubers blew themselves up? I suspect most of them there was a good reason they blew themselves up, and most of them were not because of the design of the rifle. I'm not a Youtuber and I don't know much about what goes on there, but I did watch one video of a guy nearly dying because of the terribly designed rifle he was shooting fail. He nearly died, because the designer of the rifle failed to understand and adopt a solution that was made over 100 years prior.

I've blown up a few Mauser's, I've shot them with excessive headspace, as said above, don't get worked up. Exam the why, and the how. Far too many people get wrapped up in what happened without examining the cause.

 

[Berthier]

“beware of free advice”, but here is some, honestly offered:

buy yourself a ‘field’ headspace gage, like this:

Forster Headspace Gage 8 X 57 Mauser Field HG8X57F for sale online | eBay

Find many great new & used options and get the best deals for Forster Headspace Gage 8 X 57 Mauser Field HG8X57F at the best online prices at eBay! Free shipping for many products!

www.ebay.com

from wherever you choose (Graf Brothers, Midsouth shooters supply, brownells, Natchez shooters supply, midway usa, Scheetz, etc)
follow the instructions, but if the bolt will close on a field gage, it’s probably unsafe to fire. what happens with ‘too much head space’ is that the chamber is 10-20 thousandths of an inch too long, (due to wear on the bolt lugs) & the cartridges stretch to fit the chamber, until they burst just forward of the head/extractor groove.( the ‘butt’ of the cartridge is unsupported by the chamber walls) In a rifle not designed as well as a Mauser 98 is, this could result in eye or facial injury to the shooter, even death. But these rifles are old, so don’t tempt fate, even considering the layered ‘fail-safes’ of the design, excess headspace needs to be fixed by a competent, old-time gunsmith, or at least another bolt that does pass. when you look closely at cartridges from a rifle with marginal -excessive headspace, you can see signs of stretching, & if reloading, they’ll seem excessively long. (because they’ve stretched) If you reload, don’t push the limits, if you reload using surplus components, be wary of bullets that haven’t left the barrel after an apparent ‘misfire’.

when I buy a rifle of unknown provenance, I put it in a shooting rest & fire it from 25’ away. if it doesn’t blow up after 2-3 rounds of standard ammo, I figure its OK, but then I’m 70+ YO, so maybe my perspective is different than yours.

Enjoy your ‘new’ rifle!

I find headspace gauges to be useless even if SAAMI wasn't messing around with the dimensions with pretty much all non-US milsurp cartridges. This is why US spec 8mm is loaded pretty anemically. .303 the British MOD considered safe all the way until .074 inches, with a wartime emergency allowance of .080 inches. For SAAMI the maximum allowed is .070 inches. Every Arisaka will fail a headspace check, no matter if the rifle is mint and matching.

Bolt action rifles aren't machine guns. The barrel will be worn out long before excessive headspace props up.

I know some will say, yeah but it's just piece of mind. Well, that piece of mind causes people to start switching bolts and bolt heads out to get super tight chambers to the point you can now have insufficient headspace something that actually is dangerous unlike excessive headspace which mostly just effects the function of the gun.

 

[Muncher 1953]

Berthier,

it’s ‘peace’ of mind.

Below is an example of a ‘piece of mind’ : (since you quoted my post)

when I wrote “beware of free advice” I was poking fun at myself, but you’ve illustrated my warning perfectly.

Perhaps accurate, but irrelevant info. Enfields & Arisakas are NOT the same as model 98s, and generalizing across the designs could be dangerous to the guy who asked the question. Yes, often too much fuss is made about excess headspace, but insufficient headspace in period-built Mauser actions (not rebarrel jobs or custom rifles based on model 98s) is rare enough to not be a real concern, and really not worth mentioning, you’re just giving the poor guy something else to worry about that isn’t real. You stated that SAAMI is ‘messing around with the dimensions’ but quote their allowable headspace spec as if it’s gospel. You can’t rationally argue it both ways.

Have a nice day!

 

[Berthier]

Berthier,

it’s ‘peace’ of mind.

Below is an example of a ‘piece of mind’ : (since you quoted my post)

when I wrote “beware of free advice” I was poking fun at myself, but you’ve illustrated my warning perfectly.

Perhaps accurate, but irrelevant info. Enfields & Arisakas are NOT the same as model 98s, and generalizing across the designs could be dangerous to the guy who asked the question. Yes, often too much fuss is made about excess headspace, but insufficient headspace in period-built Mauser actions (not rebarrel jobs or custom rifles based on model 98s) is rare enough to not be a real concern, and really not worth mentioning, you’re just giving the poor guy something else to worry about that isn’t real. You stated that SAAMI is ‘messing around with the dimensions’ but quote their allowable headspace spec as if it’s gospel. You can’t rationally argue it both ways.

Have a nice day!

My point about SAAMI and their specifications is that your headspace gauges will always be incorrect. If you can't test them to their original design specifications then what's the point?

 

[Muncher 1953]

My point about SAAMI and their specifications is that your headspace gauges will always be incorrect. If you can't test them to their original design specifications then what's the point?

So are you saying to ignore excess headspace because the gages aren’t available?

Though imperfect, I say one can still interpret the results, and reliably.

At least a person can buy gages for 8x57 Mauser, try & find them for 7.65x53!

 

[Berthier]

So are you saying to ignore excess headspace because the gages aren’t available?

Though imperfect, I say one can still interpret the results, and reliably.

At least a person can buy gages for 8x57 Mauser, try & find them for 7.65x53!

I'm saying that undersized SAAMI gauges are worse than nothing as they aren't correct. It's like having your speedometer in your car read 20 miles an hour low.

 

[Amateur_Gardener]

To the OP, you may find the below thread on headspace useful or interesting. There is some good advice that helped me. Also some photos that illustrate what fired brass from a rifle with excessive headspace can start to look like, especially when brass that is relatively brittle is used. It sounds like the brass from your rifle doesn’t look like this.

The rifle in the linked thread did indeed have quite excessive headspace (and the bolt closed easily on the field gauge), which has now been remedied. However, even when giving the case separations it didn’t do anything dramatic (like explode). The only thing out of the ordinary except the damaged brass was that the bolt was very stiff to open after firing.

Damaged brass / headspace / case separation

Hi all I wondered if anyone has any knowledge or experience of intermittent brass damage or case separation issues? A recent range visit has concerned me. The attached photo shows three 8x57 cases. All fired from the same rifle (a 1942 JPS with a good bore). All first use from the factory...

www.k98kforum.com

Best AG

 

[Metal]

Thank you so much for your detailed input! These are such good advices. I will get myself a pair of gauges just to be safe. I only shoot modern manufactured ammos and thankfully I didn't notice any uneven stretches whatsoever.

Try this, get yourself a pack of brass shim stock. It will have 002”,003”005”& 010 thousandths sheets.
Cut out discs from each thickness the size of your 8x57 case head. Mark the thickness on each.
Remove the striker assembly, that is firing pin, spring and cocking piece, from your bolt. You MUST do this if checking live ammo!!!
Use grease to stick one 005”shim to the bolt face.
Clip a cartridge to the bolt face and feed it into the chamber, the bolt may or may not close. Hold the rifle vertically, and ONLY do this outdoors in a safe location.
Add or subtract shims to determine the headspace of your chosen ammo in YOUR rifle.
Ideally you want 002” to 005” thousandths.
Some factory ammo has over 010 thou which I would avoid.