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SandMan_7.62
September 28, 2002, 05:42 PM
Today I was going through some "Tales of the Gun" episodes that I recorded a while back and found the one about the history of Mauser firearms. I was watching a segment of the episode when one of the firearms historians began to discuss the safety of the mauser design; basically saying that once the shooter has closed the bolt on a fresh round, nothing bad could happen because of the two bolt safety lugs, etc, and that the chamber could literally contain 100,000 psi.

I recently purchased a vz-24 with a matching stock and reciever, but a bolt that does not match. Will a bolt that does not match the rifle in any way compromise the safety of the design?
The other question I had: suppose I was to shoot my mauser and have too much headspace; what is the worst case scenario? Is there any way that a malfunction of a mauser rifle could cause death or injury to the shooter or is this virtually impossible as the firearms historians suggest? If there is something that could cause death or injury while firing a mauser, could someone please explain these possibilities?

Sorry for the length of the post and the amount of questions.

Dfariswheel
September 28, 2002, 06:23 PM
To answer both your questions.
If a rifle has a mismatched bolt it may have excessive headspace, since that bolt may not have been properly fitted to that receiver.

If a rifle has excess headspace, the danger is a ruptured case head. The cartridge case will literally blow apart at the back around the case head. This sprays hot gas, burning powder, and metal fragments back into your face and eyes. Many people have been seriously injured or blinded.

A catastrophic failure could result in the receiver/bolt exploding in your face. A few months ago an employee of one of the military rifle importers had an old military rifle suffer a catastrophic failure, and was killed.

Rifle caliber arms develope a tremendous amount of pressure at firing, and if not properly contained can turn a rifle into a grenade.

We had two catastrophic failure accidents at my old gun club. In the first case, during our annual deer hunter sighting-in days, a rifle blew and 4 people got minor injuries. Three by standers got cut up, and the shooter nearly lost a finger. A pickup truck behind the line had a piece of metal penetrate the roof, just above the windshield.

In the second case, the shooter was badly cut up, and his 8 year old daughter nearly bled to death. The front 2/3's of the rifle barrel was found 25 yards down range.

The first case was head space related, and the second was ammo mistakenly charged with PISTOL powder not rifle powder.

NO firearm can withstand defective ammo. Dump in enough powder, especially the WRONG type of powder, and the strongest rifle in the world becomes a bomb.

The legendary strength of the Mauser action is dependent on the rifle being in correct condition. Most causes of failure are due to something being out of spec. Improper headspace, bad heat treating, alterations that weaken the rifle, or improper/over loaded ammo are the usual causes.

critter44
September 28, 2002, 07:30 PM
I can not disagree with any of the above. However, do not become afraid that bad things are going to happen! Care in the use of firearms with the correct ammo will preclude most accidents of the type mentioned there. You DO need to have the headspace checked by a 'smith since the bolt is mismatched (although it is likely quite serviceable.)

The Mauser 98 is a very strong design. The VZ-24 is one of the best 98's going with some of the best heat treatment of the metal going. They are used for untold numbers of custom guns including 300 mags, 458 win mags, etc. They WILL take it! Further more, the 98's have a great gas-handling design for failures of the brass usually venting gas into the receiver rails, out the holes left just for such emergencies and into the mag well. The flange on the rear of the bolt is a gas shield to keep gas etc from your face. OF COURSE it CAN happen in completely catastrophic KBOOMS, but if care is taken, shooting a 98 is quite safe.

I personally know of a case where a shooter was trying loads for his custom 270 (on a VZ-24 action) where HIS SHOOTING BUDDY was doing the reloading. A few rounds of each powder charge, try 'em, load up a few with different charges. Two rounds were fired which showed MASSIVE recoil and required the bolt handle be hammered open. Found out that BUDDY was loading 7mm bullets instead of the 270's with near max powder charges. Bulets had to swage down several thousandths to squeeze thru bore! NO FAILURE, no gas leak, no harm to shooter, no setback of bolt lugs, etc.

I personally had a case failure in a Model 17 enfield 30-06 (definitely a mauser type design). A case burned or melted through in a long fissure where the brass had become corroded green. Gas went into the mag well, into the bolt races, around the firing pin, out the ports, etc. Only 'harm' was a bit of lube oil from inside bolt blown into my face. LUCKY! Believe me, I don't shoot ammo even hinting of green any more!

Again, bad things CAN happen but just be careful as you would with ANY gun and the 98's are wonderful toys! GOOD LUCK AND BE SAFE!

James K
September 28, 2002, 07:45 PM
A friend and I once looked at our joint Mauser collection, which was about 11 guns. We decided to check out headspace. First, we checked out each gun (field gauge). All were OK. Then we tagged the bolts, swapped them around, and again checked headspace. All were OK. After dozens of different combinations, all OK, with Mausers from at least 8 different factories in 4 countries, we decided that they did a pretty good job of keeping in specs.

As to safety, there are stronger rifles, like the Remington 700. But most are push feed rifles, which have their own potential problems, like shoving a fresh round into the primer of a chambered round (the real reason for "controlled feed").

Yes, I would have the headspace checked, and then not worry about it. Barring we elect some nut who melts all the guns, that VZ-24 will probably be shooting long after we are both gone to the great range in the sky.

Jim

Clemson
September 28, 2002, 07:46 PM
No argument with Dfariswheel, but there are a few things that you should be aware of. I have never seen a VZ24 with a matching bolt. Apparently nearly all of them were mixed and matched at some time. It would be a very rare event if you got dangerously excessive headspace in one. You should, of course, get it checked. The Mauser 98 design improvements over earlier Mausers included better gas handling capabilities in the event of a case rupture, and that is what you would get if you had a failure due to excessive headspace.

The fellow who had the unfortunate, deadly accident aparently ignored signs of excessive pressure and continued to fire his rifle. If you see signs of headspace problems like hard bolt lift after firing, excessive recoil, pierced or backed out or flattened or cratered primers, head separations, etc., for goodness sake stop shooting!

Wear safety glasses when you shoot any rifle, but particulary when you shoot your milsurps.

critter44
September 28, 2002, 08:05 PM
BTW I own and shoot 6 unmodified '98's including two VZ-24's. Two are made by Steyr of Austria between 1912-14 and rebarreled by the govt of Chili in 1961 to 7.62 Nato. I have 4 guns made on 98 actions: a .270 win on a Nazi war era action, a 25-06 on a 1909 Argentine action and two 35 Whelens, both of them are on VZ-24 actions. So, you see, I like the Mauser 98's! ENJOY!

Art Eatman
September 28, 2002, 09:08 PM
I don't pretend this is Gospel: As near as I can tell from reading, the normal upper pressure limit of some 50,000 to 55,000 psi for most rifles is based upon the strength of the cartridge case. This primarily pertains to those which have the rear portion unsupported, as in the Mauser.

This range of pressures is based upon a safety factor of some 50%, if not more. It DOES assume modern, newly manufactured cartridge cases.

At some point, it seems to me, we gotta ask ourselves which is more costly: Decent ammo, or a ruined eye and/or a ruined rifle.

Art

Gewehr98
September 28, 2002, 11:39 PM
I was being stoopid, and just had to shoot up a batch of WWII German 8mm ammo. Sure as heck, one of the primers pierced, and I felt a rush of hot gas. Just like Herr Mauser intended, the majority of the vented gas went down into the box magazine, through the pressure relief holes in the bottom of the bolt. That big bolt shroud flange kept the soot off my face, too! Made me a believer in the design, for certain!:D

Cosmoline
September 29, 2002, 02:29 AM
Nearly all the VZ-24's, and most mausers out there now, have mis-matched bolts. Nothing to worry about, as long as headspace checks out good. They are amazingly strong. Far stronger, in fact, than most modern bolt actions. They use the VZ-24 receiver for safari rifles, and I'm quite sure the action on a '98 in good condition can cope with 70,000 + PSI. You can't say the same about most American military bolt action rifles, including the legendary 1903 Springfield. I have never heard of a '98 killing anyone, though I have heard of several serious injuries from 1903's blowing up.

CAVEAT--pre-98 Mausers had two or even one locking lugs, and were not nearly as strong. Sometimes they are marked as '98's when they are not, esp. with Turks. Look for the three distinct lugs on the bolt.

Art Eatman
September 29, 2002, 10:00 AM
Seems to me that if the headspace is good, the match ain't mis-. :)

Art

cracked butt
September 29, 2002, 11:45 AM
If I were to pick any rifle that were to have a castastrophic failure of some kind that I had to shoot, it would be a Czech made 98. It has enough safety features to give you the best chance of coming out alive and in one piece.

I've had a few punctured primers with mauser 98's and didn't even realize it until I checked the fired case. No hot gasses hit me in the face though I could smell the ammonia smell before I opened the bolt.

If the bolt headspaces ok, there should be no problems at all. If the headspace is marginal, doesn't close on a field gauge, I would only use new brass and wouldn't reload for it, or at the very least would only neck size the fired cases.

The Mauser 98's are very safe, though I wouldn't experiment with pushing the limits on it. A rifle that is in poor condition is not the same as a rifle that is like new in condition. Even a Mauser 98 won't keep you in one piece if you tried to shoot oversized bullets loaded with a full casefull of Bullseye.

SandMan_7.62
September 29, 2002, 12:45 PM
Thanks for all the replies. I am not planning on reloading any 8mm; Im just gonna stick with surplus ammo. Several of you have suggested that I get the headspace checked by a gunsmith. Would this be the same as buying a go-no-go gauge and checking it myself or is extensive knowledge of firearms required to do this?

Also, what exactly causes a pierced primer?

Dfariswheel
September 29, 2002, 02:01 PM
If you want to check headspace, and can afford the gages, you can do it yourself. Just get the chamber and bolt face REALLY clean first.

Pierced primers can be caused by a number of reasons, including a mis-shaped firing pin tip, firing pin too long, firing pin hole in the bolt enlarged, over pressure ammo, and improper headspace.

Unkel Gilbey
October 1, 2002, 09:33 AM
A cheaper way to make a guess at headspace is to try the following.

1) disassemble the bolt and remove the firing pin (striker)
2) clean the bejesus out of the chamber and the bolt, especially the bolt face.
3) take a piece of masking tape, and put it on the case head. trim it so that just the case head is covered. No wrinkles allowed, just one layer of tape.
4) carefully chamber the round and attempt to lock the bolt down.

Common masking tape is somewhere around .005 - .008" thick. Having a micrometer handy will give you a good indication as to the thickness of your particular brand. By placing this on the case head, you effectively make that round that amount larger than standard. This (of course) assumes that your ammo is made to smack dab in the middle of spec. So adding that extra 5 -8 thousanths gives you a NOGO gauge - because typical tolerance for a GO chamber is .006". (In my M1 Garand books).

I would think that if you were to do this with your Mauser, and the bolt closed on a round with (let's say) an extra .006" added to it, you could safely say that your headspace was a bit too long. I'd be checking the primers on fired cases to see if they had started to back out.

Hope this helps.

Unkel Gilbey

jdege
October 1, 2002, 09:56 AM
Are matched bolts in VZ-24's really that rare?

I inherited one from a great-uncle, (who brought it back from the war), and it has matching serial numbers on stock, receiver, and bolt.

It shoots just fine, but I didn't think it was at all unusual.

foghornl
October 1, 2002, 10:12 AM
Would the masking tape "no-go" work for the Mosin-Nagant series of rifles, too? Say the 91/30 and M-44 in 7.62X54R

Unkel Gilbey
October 1, 2002, 05:08 PM
The tape on the base of the cartridge effectively makes it that much longer. With rimless rounds like the 30-06, or the 8mm Mauser, the headspace is the distance between the face of the bolt, and a reference point on the shoulder of the cartridge.

Rimmed catridges like the 30-30, and the 7.62x54 Russian are rimmed. These types of cartridge headspace on the rim - meaning the distance between the boltface and the front of the rim.

This means that a layer of tape on the base of the catridge should give you an indicator of excessive headspace... in theory. I don't have any experience with headspacing rimmed rounds, so I don't know if you'd use the same tolerance (ie: .006") of a rimless round in making that determination. If nothing else, it gives you something tangible the work with. For example: Bolt closes on round, but won't close with round w/tape, result - possible GO.

Another thing to remember, and this is why I called this a cheap way to make a guess at headspacing. TAPE IS SQUISHY! There is definitely some mush to the tape, especially with some of the 'baby huey' types out there. I'd take any 'measurement' made with this method with a grain of salt. There is really no substitute for a well maintained and properly used headspacing gauge. The tape method can be used to confirm your suspiscions about excessive headspace, but I wouldn't put all my trust in it.

Good luck,

Unkel Gilbey

telewinz
October 1, 2002, 06:20 PM
Although this test was done over 50 years ago by the NRA(?) it still applies. They took a Japanese Ariska (Mauser 98) bolt action military rifle and tested to see how strong it was. As I remember at about 80,000 psi the Ariska was the only one still functioning normally. None of the other rifles blew but they did sustain some damage such as blown extractors that indicated they were at there limit. If I remember correctly, at an estimated 100,000 psi the cartridge case failed BUT the action still held. The author of the article said at the conclusion of the test he took measurements of the receiver, ect. and found that they were still within normal limits. He said he used the action to have a custom sporter made. I'm sure their are others who remember reading this test.:eek:

Art Eatman
October 1, 2002, 11:12 PM
Yup. Remember.

I also remember that if the headspace is proper and the reloader has enough brains to pound sand, the problem is, as they say, academic.

:), Art

Unkel Gilbey
October 2, 2002, 01:57 PM
My favorite Jap Arisaka story comes straight from P.O. Ackley's Handbook. In it he recounts about how a Type 38 Arisaka was brought into a gun shop by its owner - who wanted to sell it. The owner had done some work to it, but said that it 'just kicked too much' and needed something that wouldn't abuse his shoulder. The owner did say that it was used to take a deer, and so wasn't that bad of a rifle.

The shop owner took the rifle, and then began his quest to find out exactly why the rifle was such a hard kicker. What he found was truly amazing.

It appeared that the former owner took the rifle and rechambered it to 30-06. Anyone who knows anything about the T38 Arisaka knows that this rifle had a 6.5 bore. The chamber is also much shorter than the standard 30-06. In order for this guy to make the change, he just ground down the pilot of a standard 30-06 chamber reamer until it fit the bore, and proceeded to cut the new chamber. No other modifications were made to the action.

So, imagine. Every time this guy fired the weapon, a .308" bullet was swaged down to approx .264" as it was shot out the end of the barrel. The standard 30-06 round usually makes somewhere in the neighborhood of 50,000 c.u.p! Who knows what pressures this rifle was seeing. The rifle never blew up, and was accurate enough to take a deer! No kidding it kicked too much!

If I recall correctly, the action was rebarreled, and functioned as advertised! Now, THAT is one strong action!

Unkel Gilbey

telewinz
October 2, 2002, 05:02 PM
I read that PO story too, strange but true!

Cosmoline
October 2, 2002, 06:00 PM
I think that guy was onto something. A .308" 200 or 220 grain bullet turns into a 6.5 mm!! Can you imagine the sectional density? It would be like a supersonic crossbow bolt!

BeCoole
October 2, 2002, 10:11 PM
Hey Unkel Gilbey,
I just have to chime in on this one before everybody runs off to the gunsmith with Mausers that don't headspace "properly".
That tape trick doesn't work with bolt actions. Works OK with FALS, but not Mausers. The camming power of the action is too great. I had one that would take a cartridge plus 4 :eek: pieces of tape. (That should be like .020 over!) Took it to the smith because I was afraid to fire it. He suspected something was up and used sheet metal instead. Turns out the gun wouldn't close on one piece of .004 steel sheet metal.