Minor Mauser Mishap

Hey everyone
A few months ago I bought a sporterized Peruvian Mauser Modelo 1932 (VZ 32 BRNO made action ) and it had been re-done many years ago. The original stock removed and a walnut Fajen commercial stock was added, it's ancient hard rubber but pad had gotten solvent on it at some point and is partially melted. The original military barrel was countoured/turned-down to a light profile and a set of Williams sporting irons sights were added to the barrel. The bolt handle was extended and bent down and welded with nickle rod,its tall stripper clip guide was ground off and the receiver was drilled and tapped for an unknown and now missing set of rings. Add to that a light layer of rust and 7.65Argentine chambering and you have a $100 dollar donor rifle.

I also found a 1896 Swedish Mauser barrel that had a broken receiver still attached dated 1899 and made at Carl Gustave. Though the Receiver was totaled but the barrel was in EXCELLENT condition!!!! So for a $100 dollar bill I got both the rifle and the barrel!!! And since I new the 1932 Peruvian is a 98 but a small I ring I knew was good to go with the older Swedish Mauser barrel...

Despite deciding to re-barrel the rifle I have been holding out for a box of 7.65x53mm ammo to turn up just so I could shoot the rifle before re barreling it. And eventually this week I came across a partial box of 150 grain Norma factory 7.65ARG.

Just perfect....Or so I thought....

So I headed to the range with my 6 rounds and a shoot and see target and my spotting scope. I found a spot at the 50 yard line set up my target. Got into sitting position and fired a single shot.

The rifle made a strange sound almost like a clang and had very little recoil. I ejected the spent casing and it looked very strange...the case had a shoulder but no neck... there was a deep ring (almost a a crack) half way around the web of the cartridge case (thank goodness for Norma Brass) also the primer was flattened and had spread deeply into the pocket. The 7.65 Argentine had fire formed into another cartridge.

I did not fire another round...I headed home to do some comparative inspection. I compared it to the .308 and it was far too long....so I compared it to a .30-06...Bingo...the chamber had be re bored. Next I attempted to chamber a .30-06 case and it was super tight, I had a hard time opening the bolt when I did a un-bulleted cartridge came out! I took a metal cleaning rod and punched out the stuck bullet. So not only was it re chambered to .30-06 this had been done rather poorly and was too short.

Looks like my idea to re-barrel it to 6.5x55SE was a correct choice....as soon as I get an action wrench that .31-06 wildcat barrel is coming off and getting cut up.

So a word to the wise always pour a chamber cast.

Jonnytoobad

Now that was a waisted time,but at least you wern't hurt.Just your wallet

Rechambering the 7.65 Argentines with an '06 reamer was a very common mod some years back before case trimmers were readily available and case forming was not attempted or contemplated by most, even the most experienced reloaders. Just using '06 cases made sense back then as the same was done with many 8x57s making them 8-'06s. Both cartridges are actually quite good. If that barrel is a good one I would just use some '06 cases and see how it shoots before rebarreling or cutting it up. No special dies needed; just '06 dies and a .31 M die and .31 cal moulds (recommend the C312-185-2R or the 314299). It is a good cartridge actually.

Larry Gibson

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Originally Posted by Jonnytoobad

Hey everyone
A few months ago I bought a sporterized Peruvian Mauser Modelo 1932 (VZ 32 BRNO made action ) and it had been re-done many years ago. The original stock removed and a walnut Fajen commercial stock was added, it's ancient hard rubber but pad had gotten solvent on it at some point and is partially melted. The original military barrel was countoured/turned-down to a light profile and a set of Williams sporting irons sights were added to the barrel. The bolt handle was extended and bent down and welded with nickle rod,its tall stripper clip guide was ground off and the receiver was drilled and tapped for an unknown and now missing set of rings. Add to that a light layer of rust and 7.65Argentine chambering and you have a $100 dollar donor rifle.

I also found a 1896 Swedish Mauser barrel that had a broken receiver still attached dated 1899 and made at Carl Gustave. Though the Receiver was totaled but the barrel was in EXCELLENT condition!!!! So for a $100 dollar bill I got both the rifle and the barrel!!! And since I new the 1932 Peruvian is a 98 but a small I ring I knew was good to go with the older Swedish Mauser barrel...

Despite deciding to re-barrel the rifle I have been holding out for a box of 7.65x53mm ammo to turn up just so I could shoot the rifle before re barreling it. And eventually this week I came across a partial box of 150 grain Norma factory 7.65ARG.

Just perfect....Or so I thought....

So I headed to the range with my 6 rounds and a shoot and see target and my spotting scope. I found a spot at the 50 yard line set up my target. Got into sitting position and fired a single shot.

The rifle made a strange sound almost like a clang and had very little recoil. I ejected the spent casing and it looked very strange...the case had a shoulder but no neck... there was a deep ring (almost a a crack) half way around the web of the cartridge case (thank goodness for Norma Brass) also the primer was flattened and had spread deeply into the pocket. The 7.65 Argentine had fire formed into another cartridge.

I did not fire another round...I headed home to do some comparative inspection. I compared it to the .308 and it was far too long....so I compared it to a .30-06...Bingo...the chamber had be re bored. Next I attempted to chamber a .30-06 case and it was super tight, I had a hard time opening the bolt when I did a un-bulleted cartridge came out! I took a metal cleaning rod and punched out the stuck bullet. So not only was it re chambered to .30-06 this had been done rather poorly and was too short.

Looks like my idea to re-barrel it to 6.5x55SE was a correct choice....as soon as I get an action wrench that .31-06 wildcat barrel is coming off and getting cut up.

So a word to the wise always pour a chamber cast.
Jonnytoobad

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http://milpas.cc/rifles/ZFiles/Bolt%...0Info/peru.htm

When recommending a chamber case it is always assumed the person doing the chamber cast reads the instructions, there is no shortange of cerosafe around here, I do not use it.

I measure the length of the chamber first, firing a 308 W in a 30/06 chamber will not cause high pressure, in fire forming time is a factor, before the pressure can get serious the case must fill the chamber, and that take time.

Firing a 7.65mm53 in a modified 7.65mm06 chamber does not cause high pressure, after firing the 7.65mm53 in the 7.65mm53 chamber the case is ejected as a 7.65mm06 case with no neck and a hint of a shoulder, the case shortens when the case fills the chamber, the neck is pulled back and becomes part of the case body and that little hint of a shoulder.

I have fired 8mm57 cases in an 8mm06 chamber, cases after firing came out looking like 8mm06 cases with out necks and a hint of a choulder.

Head space: The difference in length between the 7.65mm57 and the 7.65mm06 is .188 meaning the shoulder of the 7.65 is off the shoulder of the 7.65mm06 .188, the case is held to the rear of the chamber with the extractor causing the case to fill the chamber, PROOF: No neck, had the case case head space on the shoulder the case would have had to stretch .188 between the part of the case that locks to the chamber and bolt face. EXCEPTION: Bench resters that grease their cases for slide and glide shooting.

When shooting 8mm57 ammo in a 8mm06 there is .121 difference in length between the head of the case and shoulder of the case, when the 8mm57 is fired in the 8mm06 chamber the case body part if the shoulder and the neck of the case becomes part of shoulder, again, meaning the extractor held the case to the rear and the case filled the chamber. Then there is that other mistake, shooting 8mm ammo in a .308 diameter barrel. Firing an 8mm57 round in a 30/06 chamber will crush the head of the case, loosen the primer and expand the diameter of the flash hole, the crushing of the case head is the cause of the incipient case separation, because? the case body is locked to the chamber when the case head is driven back into the bolt face. It is possible to render your rifle scrap by shooting bullets that are too large in diameter, the practice is a bad habit.

Then there was Hatcher. He knew the case would not stretch .080”, so he moved the shoulder of the chamber forward .080” then fired 30/06 ammo in his new creation, he created the 30/06 Hatcher Modified +.080”. Hatchers cases shortened.

F. Guffey

(thank goodness for Norma Brass) Weird sound and no recoil? I am the fan of using new, unfired brass when forming, I form first then fire, others fire first and become fire formers, my fired cases are once fired cases.


F. Guffey

I was aware that fire forming doesn't usually doesn't cause high pressures. Because the case is expanded and that in itself uses some of the pressure to stretch the brass. I was surprised that the round nearly had a crack all the way around it. The 7.65Argentine ammo I fired was factory loaded Norma with NP marked primer, not reloaded Norma ammunition. Perhaps the case just stretched too much??? But I am not sure. The other part that is wierd is that it won't chamber a .30-06 round without serious force so I don't think it has been fully reamed to .30-06 length.

Also I'm sure .31-06 isn't a bad cartridge, but I have no need for it and I don't think that the chamber is deep enough to begin with so I'd like to take it out of circulation....Also I really want to re barrel this rifle to 6.5x55.

Jonnytoobad

No problem here with the rebarrel if that's what you want to do. I only posted because you mentioned "cutting" it up and if the barrel is still good someone might want it is all. It's your rifle, you want the 6.5 Swede then go for it. I've a sporterized SR M98 I've rebarreled to 6.5 Swede and it's a very good shooter.

Larry Gibson

I have a Peruvian that is .30-06 with a .310 groove, shoots just fine. I'm not sure what the issue is. .310-.311 bullets and boolits
are readily available, should be no issue to load and use as it stands, unless you just need a new caliber.

Bill

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Originally Posted by MtGun44

I have a Peruvian that is .30-06 with a .310 groove, shoots just fine. I'm not sure what the issue is. .310-.311 bullets and boolits
are readily available, should be no issue to load and use as it stands, unless you just need a new caliber.

Bill

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“Should be no issue to load and use it as it stands” The OP says he chamber a 30/06 round in the chamber and had trouble closing the bolt “Next I attempted to chamber a .30-06 case and it was super tight, I had a hard time opening the bolt when I did a un-bulleted cartridge came out!” .

“I'm not sure what the issue is” and? I do not know, but, if a 30/06 case chambers with resistance it is a very safe bet the chamber is not finished, it is a safe bet the chamber is what I call a ‘short chamber’. A case can be sized for a short chamber, all a reloader is required to know and understand is the technique of raising the deck height of the shell holder. Some grind the top of the shell holder, others grind the bottom of the die, both methods are bad habits. With a RCBS holder it is possible to reduce the length of a case by .012” between the head of the case to its shoulder.

“I'm not sure what the issue is” I am sure the issue with failing to chamber a 30/06 case is not caused by chambering a case in a control feed rifle like it was a push feed rifle, but, stranger things have happened.

F. Guffey

Jonnytoobad,

Try making up some dummy 6.5's and see if they feed and extract OK before investing time in the rebarrel. Usually it is no problem, but as you found out you can't take anything for granted.

HF

Case had a bullet in it, which stuck in the throat. It probably doesn't have a throat. May have had only the chamber reamed, short, as in non-existent, throat.

@fguffey - did it not register that the O.P. almost had a case head separation? Is everything we've learned in the last hundred and twenty years about the dangers of excess headspace in a rimless bottleneck case wrong?

If the bore is .310 or .311 (original) and the chamber is .30-06, a handloader can make
ammo for it. If the throat is short, then reaming or deep seating may be required.

It would seem that making ammo for this hybrid ONCE IT IS PROPERLY IDENTIFIED should
be well within the capablilities of a handloader. I wasn't implying that it was going to be
a gun that will work as is with factory ammo, I thought the discussion had moved far
beyond that point to whether the bbl was junk or could be used.

Bill

Bill
I understood where you were going with it, I was only considering cutting it up because I didn't want to create a hybrid cartridge and I didn't want someone who didn't to know end up with it. I am suspicious that the chamber is not fully reamed so the best thing would be to ream it again properly with a new full length .30-06 reamer.
Thanks for all the interest and concern...I'll think Ill pour a sulfur cast and see what the neck area looks like.

Hangfire
The 6.5X55 dummies is a great idea! I am a huge fan of comparative testing before doing anything too drastic.Now I have several live 7.65X53 and they fit in the box magazine perfectly (not suprisingly)but the 6.5 will be a little longer. What I do know for sure is that .30-06 do not fit correctly in the box magazine as they are too long! I think the 6.5x55 will work perfectly but I will test it for sure before hand I re learned my lesson when it comes to that.

I did some research on overall length (sorry in Metric)and I am certain that both 7.65, and 7x57 will fit in the box magazine...I just need to rustle up some 6.5X55.
7.65X53=76MM (fit)
7x57mm=78mm (fit)
6.5x55mm=80mm
.30-06=85mm(won't fit)

I don't get why they would convert the rifle to fire a round that won't fit in the box magazine, effectively making the rifle a single shot.



Jonnytoobad

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Originally Posted by Jonnytoobad

I don't get why they would convert the rifle to fire a round that won't fit in the box magazine, effectively making the rifle a single shot.

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Maybe that's related to the short chamber -- they were halfway through the conversion before they realized they'd have to make "bobbed" .30-06 rounds to be able to load them in the magazine, and just swept the mistake under the rug by selling the rifle without telling the buyer. Not smart, but then we pretty much already figured that out...

“The rifle made a strange sound almost like a clang and had very little recoil. I ejected the spent casing and it looked very strange...the case had a shoulder but no neck... there was a deep ring (almost a a crack) half way around the web of the cartridge case (thank goodness for Norma Brass) also the primer was flattened and had spread deeply into the pocket. The 7.65 Argentine had fire formed into another cartridge”

”I did not fire another round...I headed home to do some comparative inspection. I compared it to the .308 and it was far too long....so I compared it to a .30-06...Bingo...the chamber had be re bored. Next I attempted to chamber a .30-06 case and it was super tight, I had a hard time opening the bolt when I did a un-bulleted cartridge came out! I took a metal cleaning rod and punched out the stuck bullet. So not only was it re chambered to .30-06 this had been done rather poorly and was too short.”


“@fguffey - did it not register that the O.P. almost had a case head separation? Is everything we've learned in the last hundred and twenty years about the dangers of excess headspace in a rimless bottleneck case wrong?”

“did it not register that the O.P. almost had a case head separation?” Did it not register to anyone the OP chambered a 7.65mm35 in a 30/06 length chamber, the difference in length between the two cases is .210 from the head of the cases to the shoulder of the cases.

“Is everything we've learned in the last hundred and twenty years about the dangers of excess headspace in a rimless bottleneck case wrong?”

I do not know who ‘everything we’ve learned’ is, I do not know what ‘we’ve’ learned. The OP claimed “So not only was it re chambered to .30-06 this had been done rather poorly and was too short.”. He also made the statement “the case had a shoulder but no neck” He did not say it has a very short neck or a hint of a neck, he said it had ‘NO NECK’.

Please do not include me in the ‘we’ve learned’ category, when Johnytoobad fired the 7.65mm53 case in the long chamber his case expanded and filled the chamber, while filling the chamber the case shortened, proof? He ejected a case that did not have a neck, his shoulder did not move forward, his neck did not move, it was erased and became part of the case body, his neck became the shoulder, the case while forming to the chamber did not have enough case left for the neck.

No one does ‘it’ but when fire forming a reloader/case former should scribe the case body/shoulder juncture and the shoulder/neck juncture, scribing the junctures would help “we’ve” to understand what happened, I form first then fire.

Again, the neck on the 30/06 case in the perfect world is .285” long, the neck on the OP’s case did not have a neck, meaning his cases shortened .285”.

uscra112, then there was Hatcher, he moved the shoulder forward .080” knowing the case head would separate, he ejected 30/06 +080 Hatcher modified cases from his new creation.

F. Guffey

It was common to extend the box magazine or replacing it with one that was long enough. Some actions also require the grinding of a notch at the front of the action on the right side so loaded rounds will eject. In reading many of my old Am. Rifleman magazines all this and more is mentioned.
I would expect the 7.65X53 brass to seperate or close to it when fired in a longer chamber.
Have you tried an empty 30-06 in the action? As mentioned the chamber could be unfinished which is not a problem if you have or rent a chamber reamer.
I converted a Turk small ring to 6.5-06 and had to do the above to it. Not really hard to do at all.
If you want to get rid of the barrel I have quite a few 6.5X55 cases that are once fired.

When I buy old bubbaed Mauser I do a chamber cast as some as you found out are not what they are supposed to be.

Removed the old bubba'ed 7.65/06 barrel from the Peruvian Mauser receiver today. Sadly it required the use of a parting tool on the lathe to remove it from the receiver and a very strong barrel wrench to crank it off. On the positive side the Swede barrel screwed right in and looks great. Also the magazine box is the perfect length! I can't wait to crank it on and head space it.

Quote:

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Originally Posted by Jonnytoobad

Removed the old bubba'ed 7.65/06 barrel from the Peruvian Mauser receiver today. Sadly it required the use of a parting tool on the lathe to remove it from the receiver and a very strong barrel wrench to crank it off. On the positive side the Swede barrel screwed right in and looks great. Also the magazine box is the perfect length! I can't wait to crank it on and head space it.

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Jonny, I don't understand. A parting tool AND a barrel wrench? Usually one has a barrel vice and action wrench. Is this some method I'm not aware of? I'm curious. Also, what exactll is left of the barrel for I may be interested in it.

Vastly oversized chambers can prevent the charge from building up to full chamber pressure, especially if the chamber is so long that the bullet doesn't contact the throat of the bore, gas flows around the bullet.

A much lesser amount of slack in a chamber, around .03 excess headspace is about all the average case can handle under a full charge, causes the problems we are familar with. Much less excess headspace , on the order of .01 or often less, results in poor case life which is only important to reloaders.
Light charges that don't force the case to grip the chamber walls can increase caselife in a long chamber, but can result in a short sharp hammering of the boltface or lugs. Hatcher wrote of a Low Number Springfield that shattered like a jelly jar when a reduced charge guard or gallery cartridge was fired, though the rifle had held up to thousands of rounds of ball ammo.

They established that headgap of .004 was the best for accuracy around the end of the 19th century, but primers and propellents were very different when that testing was done.

In regard to feeding the 6.5X55.
If you use Wilson trimmer you will find that the 7.65 Mauser and the 6.5X55 both use the same case holder. While the two cases are slightly different in diameter they have the same taper.
The 6.5X55 should function well in a rifle originally designed for the 7.65 Mauser.

I was concerned that the action would crack as I did not have a proper action wrench. And since I didn't care about the barrel,I put it in the lathe and cut a relief to reduced the pressure from the receiver ring. Then I carefully blocked and clamped the action in a large machinist vice and put a wrench on the barrel and turned it out of the receiver ring. It worked perfectly and didn't require very much force.