My model 93 Mauser bit me!

[Slamfire]

This is very interesting. I am building three small ring projects and will make necessary modifications to minimize this threat. I will post my mods as I make them.

Something I did not know at the time I posted in this thread was that ammunition pressures rise as the ammunition gets older.

I had planned on loading light..... these were factory ammo from 1970-something..... I had 139 and 175 grain bullets. The 175's kicked like an angry mule, I had 2 or 3 pierced primers, and the case heads looked like h

Notice that the guy was firing factory ammunition from the 1970's. It had obviously gone bad, increasing pressures, and piercing primers.
Since I have learned about the risks of old gunpowder, I have been collecting a few good examples, as warnings about old cartridges and old gunpowder.





The lifetime of gunpowder is unpredictable, the Air Force calls it indeterminable, which confuses a number of people, including Air Force personnel, as they confuse indeterminable with indefinite. (infinite) Indeterminable means “not able to be definitely ascertained, calculated, or identified” Basically, the stuff fails when it fails. A reasonable lifetime for double based is 20 years, single based 45 years, but, sometimes unreasonable things happen with gunpowder. I think this gunpowder was less than 10 years old before bottles started auto combusting because the stuff had aged unexpectedly quickly.





Combustion pressures also rise in old cartridges and this is what the OP was experiencing. His action was doing quite well for an old military action. Things could have been worse as the 1892 Mauser action has few gas venting protection features. If the OP had been using new factory ammunition or reloads with fresh gunpowder, assuming proper reloads, then he would not have experienced any of the over pressure conditions posted in this thread. That is the absolute first place to start with one of these old actions. Shoot appropriate ammunition, don’t shoot decades old stuff, and stop shooting old stuff if it shoots signs of overpressure.

Don’t shoot anything that looks like this:

[4V50 Gary]

Old bad cartridges - pull bullet. Pour powder in garden (plants love it). Old brass goes to the foundry to make brass buttplates, trigger guards (flintlock/blackpowder), side plates.

[Gunny K]

In my Vz52 I have been shooting ammo marked 55-56. I have shot about 500 rounds out of the 4K I have for these rifles. The only thing I have noticed is that one out of 20 might be a dud.

[zipspyder]

Had my first ever hang fire (delayed shot?) today with my British 303. Was testing my first reload attempts with Hornady 174gr SP bullets. Waited about 10 seconds and had the rifle pointed slightly upwards. Scared the crap out of me and didn't have a really good grip. I never want to do that again...yikes.

[Mobuck]

Just my personal opinion: quit pushing those old design Mausers that hard or you'll pay a painful price sooner or later. Adjust the FP protrusion to minmize the chance of primer perforation.

[jdh]

My choice for a young girl would be something like a Ruger American Predator in something like a 243 or a 6.5 Creedmoor. There are plenty of reasonably priced factory offerings that are suitable for younger shooters. I would get something stocked suitably for her to shoot comfortably.

Old military rifles are fun to play with but they were made for cartridges that develop less pressure than modern loads and I would stay away from old surplus loaded ammo. Most of it wasn't very reliable when new. That said the mod.98 re-barreled to a mild chambering should be fine if done correctly by someone that knows what he is doing. Those usually don't come cheap.

Joe

[Gunny K]

I do agree about the FP protruding a lot. But one thing we have to take into consideration is that in those days almost all primers were Berdan with a built in anvil on the cartridge. This really smashed the surface of the cap. On modern Boxer primers the anvil will crush under hi FP impact pressure. I personally have never heard of a modern Boxer primer being penetrated. But having said that, I still believe that the FP protrusion should be adjusted to a reasonable distance. The best and safest place to do that is at the base of the cocking piece. Placing a shim on the firing pin inside the shroud.
I have also performed the modifications to my bolts and firing pins to allow gasses to escape if penetration ever do occur. I attached some pictures. Please note that at this point the firing pin has a left and a right. The opening is 3/16 x 3/8 approximately 1/8 in front of the extractor ring.

[Gunny K]

Originally Posted by jdh

My choice for a young girl would be something like a Ruger American Predator in something like a 243 or a 6.5 Creedmoor. There are plenty of reasonably priced factory offerings that are suitable for younger shooters. I would get something stocked suitably for her to shoot comfortably.

Old military rifles are fun to play with but they were made for cartridges that develop less pressure than modern loads and I would stay away from old surplus loaded ammo. Most of it wasn't very reliable when new. That said the mod.98 re-barreled to a mild chambering should be fine if done correctly by someone that knows what he is doing. Those usually don't come cheap.

Joe

I have quite a few 98s and they are chambered in full length Magnums such as 450 Ackley, 300-8mm Rem Mag, 375-8mm Rem Mag, 376 Steyr, 338 Win Mag, 6mm- 6.5mm Rem Mag Improved. Never had a stitch of problems or any evidence of trouble. However they are all Vz-24s. I shoot the two 375s a lot. must have close to 1K rounds through each.
The Small rings I am building are 7.62x45 Czech on two Turks and a 243Win on a Spaniard.

[Paul B.]

"Something I did not know at the time I posted in this thread was that ammunition pressures rise as the ammunition gets older."

If your ammo it that old and you're getting pressure signs try running them through the seating die with the die adjusted about one half to one full turn deeper. Sometimes the brass and copper bullets "cold weld" themselves and this will all kinds of merry hell with high pressures. When you do this, you should hear a slight "click" as the weld is broken.

I have a batch of .270's I loaded back in 1970 according to the notes on the box. Powder is that old milsurp 4831 to boot. I should either break them down after first reseating as mentioned above of reseat and shoot for practice ammo. Either should be a win win situation although I'll first break one down to check powder condition. I shot up a bunch of LC 51 30-06 ammo last year with no problem and that stuff was 65 years old. All sent bang and shot nice groups without a problem.

I haven't messed with a 93 Mauser since 1973/4. I think that as long as one stayed with factory level loads there shouldn't be a problem. If you want to bring the 7x57 up to modern pressure levels, use a rifle based on a modern action. If I were doing a deer hunt, or even one for elk and could be reasonably sure my shots would run 200 yards and less, I wouldn't worry about my 93/95 Mauser not working with plain old Winchester 145 gr. Power Points (if you can find any) or the the 175 gr. Hornady load. An equivilant handload with 150, 160 or 175 gr. bullets would also work just fine. Just remember your range should be limited to 200 yards or less.
As far as gas vents on a 93, frankly I honestly don't remember. Might be a good idea if there are none is find a competent gunsmith and have him put the escape hole in the receiver and the two holes in the bolt. Should help with escaping gas.
Paul B.

[HiBC]

I don't know the full story.There is some controversy whether it was a experimental semi-auto or a small ring Mauser that was involved,but Paul Mauser himself lost his right eye to gas escape and IMO,that had something to do with retro-active corrective measures on Mausers.

Maybe that's the 1916 thing. But I don't know for sure.

There is another factor in blown primers(among the many). The condition of the bolt face and firing pin hole.These wear/erode.

Old single shot gunsmiths "bushed firing pin holes" for a reason.

The greater gap you ask brass or primers to span,the more likely they are to fail.

Maybe its just me,but,if I'm starting a 12 yr old girl hunting or ice fishing or anything....I can get by with the old clunky equiptment.I'll use the Mauser and the clunky old boots.
And she'll have(If I can afford it) the CZ youth 6.5 Grendel and Merrill or Redwing or whatever good boots fit her.

That might mean an older H+R Topper break action 30-30,but it will get fitted to her like a bridesmaid dress!
She'll know its special for her.And a gun has to fit.

[FrankenMauser]

Normally, if you are using newish ammo the cause of pierced primers is not excessive firing pin protrusion but something restricting firing pin retraction. The usual culprits are dried cosmolene and little stray bits of sheared off brass in the firing pin hole from reseating primers in rifles with excessive headspace.

What?
Firing pins do not retract during the firing sequence in Mauser-style actions.

And normal firing pin retraction (while opening the bolt) is not going to pierce a primer.

[emcon5]

My choice for a young girl would be something like a Ruger American Predator in something like a 243 or a 6.5 Creedmoor.

Well, the "young girl" when this thread started was 12, now she is 19. I am guessing the rifle problem has been solved by now.

As to powder deteriorating over time, I think it really depends on the powder and how the ammo was stored. Luckily, there is a decent knowledge base for pretty much all the surplus ammo that is available, and "new" stocks of surplus ammo are extremely unlikely to appear.

Millions of rounds of surplus ammo have been shot through old military rifles over the years without incident, but as with any old ammo, you pay your money and you take your chances.

[Gunny K]

I do apologize for bringing this thread back to life. There is just very little talk about small ring Mausers, especially 93-95s and I do have five of these project actions to work with. Two Turks and three Spaniards. I just sold one A Spaniard last week to someone who has been searching for one. My two Turks will both be 7.62x45 Czech. (think of it as a 7.62x39 on asteroids). It has about 200fps more than the 7.62x39. I have a Mini Mk-X in that cartridge right now and wanted something with a 22" barrel instead of the 18" that is on the Mini Mk.-X. Also I wanted to be able and use longer bullets than can be used in the stock length action. Now I can go up to 150gr bullets instead of the 123gr bullets I have been using. One will be using Williams WGRS sight and the other a scope. One of the Spaniards is planed for a 243Win. and one for a 7x57 Mauser.

[emcon5]

I would rethink the .243 Win. .243 is a ~60K PSI pressure cartridge. The Spanish M93 action was designed for a cartridge putting out a lot less than that.
SAMMI max pressure for 7X57 Mauser: 51K PSI

It is unlikely to blow up, but you will probably see lug setback and a ruined rifle that won't headspace after a while, how log depends on how good the steel is in your particular action.

[Gunny K]

I plan on loading a bit light since I have 2 6mms that can push close to 4K-fps. I can load at mid load recommendations. I got a tight twist barrel and plan on using 95+ gr bullets and move them in the high twos, 2.8-2.9k. That should leave the pressures down below the 55K#.

[HiBC]

One of the Spaniards is planed for a 243Win.

I'm with emcon. The 243 is maybe a bit zippy.

Another issue,don't expect trouble free feeding if you go to a .308 derived case.The taper is different,the mag stackup is different.
Voice of experience.Not saying it can't be done,but....

Now the 257 Roberts is a necked down 7x57 that SAAMI specs at lower pressure....

If its a handload situation and you want to use 6mm bullets,the 6mm Rem is the 7x57 case necked

[Gunny K]

I just wanted a slower moving 6mm. Two of the Spaniards I have have already been converted to the 7.62 NATO (7.62×51mm CETME) so feeding should be no problem because the rails would alredy been modified. I have converted many a Mauser to different taper cases with no problems. This one I am not worried at all. Besides the lower steel is not Spanish but from a 6.5 Swede.

[FrankenMauser]

.243 Win is pushing the limits of a Spanish 93/16. I wouldn't go there.

And, 7.62 NATO and 7.62 CETME are not the same. The CETME cartridge runs at lower pressure ... which is the only reason the Spanish rechambered the 1916s for it. And, even then, they were last-ditch rifles - not intended for full time use.

The Spanish 93s and 1916s are relics, in every sense of the word. Proceed cautiously, if at all.


(Yes, I have several, myself.)

[Slamfire]

I just wanted a slower moving 6mm. Two of the Spaniards I have have already been converted to the 7.62 NATO (7.62×51mm CETME) so feeding should be no problem because the rails would alredy been modified.

If a Spanish 308 Win conversion blows, who you going to sue? The Spanish Nation? Just because the Spanish military or some other military converts their 7mm Mauser actions to 308 Winchester does not mean it is safe. What it means, is that the Spanish military has a callous attitude towards the lives and health of its Soldiers, Sailors, Airmen, and Marines. It was not that long ago that the US military issued low number M1903 Springfield rifles, about 1,000,000 to its troops. This was after tests that showed about 33% percent of these rifles would come unglued in overpressure incidents. Officially the statement was that the rifles would be left in service until worn out and then the receiver would be scrapped at Depot. What the press release ignored was the fact that a certain number of these rifles would blow up, injuring its user, before it was returned to Depot. The Hierarchy of the US Army, Navy, Marine Corp made this decision knowing full well the consequences to its service men. Leadership considered the life and health of a service man to be worth less than a $40.00 rifle. What makes anyone think the Spanish military were any more enlightened? The aristocracy of all nations consider their subjects as disposable for their greater good. Spending money protecting the great unwashed is not part of their greater good.

The pressure data for the M98 also applies, as far as we know, to the small ring Mausers:

Rifle Magazine Issue 159 May 1995 Dear Editor pg 10
http://www.riflemagazine.com/magazin...159partial.pdf

Ludwig Olsen :

Mauser 98 actions produced by Mauser and DWM were proofed with two loads that produced approximately 1000 atmosphere greater pressure than normal factory rounds. That procedure was in accordance with the 1891 German proof law. Proof pressure for the Mauser 98 in 7 X57 was 4,050 atmospheres (57, 591 psi). Pressure of the normal 7 X 57 factory load with 11.2 gram bullet was given in Mauser’s 1908 patent boot as 3,050 atmosphere, or 43, 371 pounds.

While many Mausers in the 1908 Brazilian category will likely endure pressures considerably in excess of the 4,050 atmospheres proof loads, there might be some setback of the receiver locking shoulder with such high pressures

Kunhausen shows similar numbers in his book : “The Mauser Bolt Actions, A Shop Manual”

Rifle & Carbine 98: M98 Firearms of the German Army from 1898 to 1918 Dieter

M98 Mauser service rifles underwent a 2 round proof at 4,000 atm gas pressure, 1 atm = 14.6 psi, 4000 atm = 58, 784 psia. Page 103. A comment on the metallurgy and process technology of the era, Dieter found records that indicated that the bolt lugs broke on 1:1000 of GEW98 service rifles used by the Bavarian Army Corp!

Gun Digest 1975 has an excellent article, “A History of Proof Marks, Gun Proof in German” by Lee Kennett.

“The problem of smokeless proof was posed in a dramatic way by the Model 1888 and it commercial derivates. In this particular case a solution was sought in the decree of 23 July 1893. This provided that such rifles be proved with a government smokeless powder known as the “4,000 atmosphere powder”, proof pressure was 4,000 metric atmospheres or 58,000 psia. The 4000 atmosphere proof was standardized for the 1893 and continued after 1911.

The article indicates it was applied to the 1898. The 1939 German proof law called for proof at 130% of service load pressure. From Mauser Bolt Rifles by Ludwig Olsen, page 134, The maximum working pressure of the German 7.9 sS cartridge was 46, 926 psi. According to sources, this round was used in machine guns after WW1 and then shortly before WW2, became a universal issue round. Use in the K98 action had to have been examined, and I expect the decision to use in the K98 would have been based on the improvement of metal quality and process technology. A proof pressure 7.9sS would be 61k psi.

So, cartridges operating at 60,000 psia are operating at the proof pressures of these old military actions. Unless someone can produce credible data as to the proof standards of later 98 actions, and the design limits used by Paul Mauser, I am going to state that it is reasonable that the small ring mausers and the M98 action was designed to support cartridges of 43, 371 psia with a case head diameter of 0.470”. Later higher pressure ammunition was probably considered an acceptable risk, but even then, the 7.9 sS World War 2 cartridge pressure was 46,926 psi.

I believe that a pressure standard for these rifles of 43, 371 lbs/ in ² is reasonable based on the SAAMI spec pressure of 35, 000 lbs/ in ². Obviously SAAMI researched this issue, probably determined original pressure standards, then used wise judgment about the age, uncertain previous history, unknown storage, usage, the known limited strength of period plain carbon steel actions, and as an industry, they were are not willing to accept the liability involved with selling new ammunition of a higher pressure.

I have converted many a Mauser to different taper cases with no problems. This one I am not worried at all. Besides the lower steel is not Spanish but from a 6.5 Swede.

When you experiment with cheap old military actions, operating them constantly at pressures above their service pressures or their intended pressures, you invite some particular and predictable risks. If the receiver seats are peened, due to high pressures, case head protrusion increases and it is only a matter of time till the case sidewalls blow. If the bolt lugs crack, through fatigue fracture, with these small ring Mausers, the bolt can be blown out. From web postings on another forum, this has accounted for at least two fatalities. I think one was a shooter in Australia and one was a Swedish Service man. After the death of the service man, Sweden dumped all their old M1896 rifles on the American market. You can, if you want, study the pressure the Swedes used, and their old plain carbon steel actions were not operating at 60,000 psia. Swedish steel may (and this is an assumption) may have been better than Spanish, but actions made prior to 1920 were pre vacuum tube technology. Spain had a Civil War in the 1930’s, so it is likely the rifle factories were not being technologically upgraded as people were cheap.

These old actions are cheap, and that is for a reason, they are cheap. They are metallurgically weaker than the same receiver made of modern alloy steels. The fatigue life is less, in fact, quite unpredictable.

If you are building these actions for others, understand your liability. As a gun manufacturer you are assumed to know more than your customer. You are assumed to be an expert. If one of your conversions blows up in the hands of another, and you converted it to an inappropriate cartridge, in a product liability lawsuit, you will lose everything you own, and everything you will ever own.

However, if you are making these for yourself: Go have at it. You are responsible for you own life and limb and if you don’t have the knowledge, and don’t heed the warnings, well, it is on your head and no one else.

[jimbob86]

Well, the "young girl" when this thread started was 12, now she is 19. I am guessing the rifle problem has been solved by now.

She is indeed 19 .... never did take a deer. Still goes hunting .... just doesn't shoot.

I still have the gun ..... none of the kids want to shoot it- it was dubbed "The Bitey Gun" by my then 7 year old son .... he still calls it that ..... kinda funny, as he's near to 6 feet tall now.....

[Gunny K]

Some years ago, When Harry McGowen was still building rifles, He built a few for me out of Mauser actions, Small and large ring. Strangely enough he was one of the most respected gunsmiths in the world when he was active in the field, before he retired. As many rifles as he has built out of small ring actions, He has never had one fail or was he sued for such a thing happening. It is good to hear all of these opinions just to see what they actually are. Truth be told, these opinions are all over the spectrum. Will a gun ever blow up? Sure it will. I remember when we first had the Beretta M9 issued to us and the slides flying off. Yes it happened once or twice but not as often as was implied. Remington now has a lawsuit against them because of there triggers going off etc etc. We all know that this can go on for ever. When dealing with firearms caution and precautions must be practiced at all times. There have been many of these Spaniards sold in the last few years and so many people, not knowing the difference, shoot 308Win through them. Has one blown up? Maybe but it is not like the www is loaded with this disaster. Yes I will practice caution. But I will not loose sleep over it. Wen all is said and done, the Remington 700 action was never intended to shoot the RUM cartridges ether, but it is being done, with no failures, (so far). Can or will it happen? Maybe.

[emcon5]

Just because it doesn't spontaneously disassemble, doesn't mean it is safe.

Like I said earlier, it is unlikely to blow up, but you will probably see lug setback and a ruined rifle that won't headspace after a while, how long depends on how good the steel is in your particular action, and how much you shoot.

[emcon5]

Missed this before:

I believe that a pressure standard for these rifles of 43, 371 lbs/ in ² is reasonable based on the SAAMI spec pressure of 35, 000 lbs/ in ². Obviously SAAMI researched this issue, probably determined original pressure standards, then used wise judgment about the age, uncertain previous history, unknown storage, usage, the known limited strength of period plain carbon steel actions, and as an industry, they were are not willing to accept the liability involved with selling new ammunition of a higher pressure.

I think SAMMI pulled that number out of their butts, as a big CYA in case some dullard shot a .323 bullet through a .318 bore Commission Rifle.

The SAMMI spec for 7X57 Mauser, which was chambered in the same rifles for the most part, is 51,000 psi. The CIP Specs for both 7X57 and 8X57 are the same, 56,560 PSI.

[Gunny K]

Proper precautions, inspections and taking care of your firearms can prevent hazardous situations.

[emcon5]

Originally Posted by Gunny K

Proper precautions,

One of which would be not chambering the rifle in something that produces 25% more pressure than the action was designed for.