1895 Chilean Mauser headspace issues, fails a NO-GO & FIELD *Updated
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Thread: 1895 Chilean Mauser headspace issues, fails a NO-GO & FIELD *Updated

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    frown 1895 Chilean Mauser headspace issues, fails a NO-GO & FIELD *Updated

    So I have this numbers matching 1895 Chilean Mauser (not a 93, has a round bolt face, straight handle). The bore is in excellent condition, nice and shiny with strong rifling, really nice rifle, does not look like it has been used much. I bought this rifle about 5 years ago from a local dealer and I never fired it. If it helps, it does have the Swiss barrel on it with markings "SJG".

    So I have the Forster headspace gauges, GO, NO GO and Field. It closes easily on the NO GO and the FIELD. Actually, it closes like their is nothing in the chamber, that is how easy it is. So how could this rifle not pass a headspace test yet being in the condition that it is in? I did take everything off the bolt and cleaned the chamber when I checked headspace. I'm glad I did not shoot this thing. Any ideas?
    Last edited by srv1; 03-05-2017 at 03:20 PM.

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    The "SJG" is German for SIG...It sounds like the original German barrel was replaced with a Swiss barrel and not headspaced correctly.

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    Fireform a round, without a Projectile, to see what it may be..

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    Do a bright light chamber inspection, then if all "looks" well, a really good chamber cast. Take care to fill at least an inch of barrel and fill chamber all the way. Do that by making a little dam around the rear of the barrel with clay. You want a little well filled "mushroom" of material to trim to exact length of chamber. If it's close to 7mmMau then you might try fire forming a case or two to see where you're at. Devil's in the details here. If you haven't done this before, be careful or get help. Have seen more than one "long" chamber made by trying to clean up some chatter marks. Maybe a candidate for an Ackley Improved to save a lot of work and still be safe.

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    You cannot correct the problem by just messing with the ctgs. It has to be set back a full turn and rechambered.

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    Quote Originally Posted by musketshooter View Post
    You cannot correct the problem by just messing with the ctgs. It has to be set back a full turn and rechambered.
    Assuming [quite the word] that is indeed chambered in 7X57...
    And I don't go a full turn...The sights are soft soldered..Turn enough to get where ya need to be, and turn the sights [after removing the set screws of course]. I dislike gaps at the inletting, etc.

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    Quote Originally Posted by srv1 View Post
    So how could this rifle not pass a headspace test yet being in the condition that it is in?
    Pretty simple really. One of my favorite rifles, built in about 1913, has one of the nicest bores I have ever seen on a european sporting rifle of the era. Absolutely mint, crisp, can still see the pull marks from the rifling cutter. The chamber is almost 3mm TOO LONG, that is .1181 for us english folks. I would guess everytime the guy fired a round it blew the case head.

    Do you have shim stock to measure how long the chamber is? If you are experienced at reloading, a few thousandths is not an issue.

    Or just sell it to me and I will fix it .

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    I do not reload nor do I have the tools or experience with what is mentioned above. It is not marked anywhere for 7.62 NATO. I could take it to a gunsmith but then it would ruin the value of the gun not to mention the costs that would be involved. Now the headspace gauges I'm using says for 257 Roberts/7mm Mauser on Forster's website. Are these the correct ones?

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    7.62 nato is shorter than 7x57. It would not close on the go if so converted.

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    Quote Originally Posted by mwt View Post
    7.62 nato is shorter than 7x57. It would not close on the go if so converted.
    That is what I thought. I always get the two mixed up.

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    i have been told of this headspace problem arising in this caliber,7mm Mauser,over the years. a good friend who happens to be a gunsmith of German heritage has described the situation as follows. the cartridge specifications given by the American SAAMI group are not the same as those used in Europe and so US mfg headspace gauges are different as well. the comments about this particular caliber,7mm Mauser,are always that the European chambers have excessive headspace when checked against US mfg gauges. regarding this particular rifle described on this page,there is a good possibility that it may work ok with "some" new ammunition. the Mauser extractor will only let the cartridge go a certain distance into the chamber when a cartridge is fired. if more stretching happens,it will occur at the cartridge shoulders at the front.
    i have owned and shot 4 or 5 of the same rifles as the one described here.used Canadian and American mfg cartridges and brass without any problems. problems may occur when using handloaded ammo with cases that were fired in different firearms. i've been collecting and shooting Mausers of all types for 35 years;the most impressive accuracy for me was obtained with a Chilean model 1895 long rifle in"7mm Mauser". cheers,FRosty.

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    I agree with Frosty...Could not say it better, nor add anything!!!
    My '95 also is the most accurate Milsurp I have.

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    Guess you better sell it to me

    Call Dave Manson and order a set of CIP gauges and check it.

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    Got a safe full of Mausers, Argentines, Brazilians, Swedes, etc and have never yet found one with headspace problems.

    I have 2 Chilean '95 rifles and a Chilean '95 carbine... They are all "tack drivers"... I shoot cheap Prvy soft-points and then reload the Prvy brass with my favorite handloads.
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    Quote Originally Posted by Frosty View Post
    i have been told of this headspace problem arising in this caliber,7mm Mauser,over the years. a good friend who happens to be a gunsmith of German heritage has described the situation as follows. the cartridge specifications given by the American SAAMI group are not the same as those used in Europe and so US mfg headspace gauges are different as well. the comments about this particular caliber,7mm Mauser,are always that the European chambers have excessive headspace when checked against US mfg gauges. regarding this particular rifle described on this page,there is a good possibility that it may work ok with "some" new ammunition. the Mauser extractor will only let the cartridge go a certain distance into the chamber when a cartridge is fired. if more stretching happens,it will occur at the cartridge shoulders at the front.
    i have owned and shot 4 or 5 of the same rifles as the one described here.used Canadian and American mfg cartridges and brass without any problems. problems may occur when using handloaded ammo with cases that were fired in different firearms. i've been collecting and shooting Mausers of all types for 35 years;the most impressive accuracy for me was obtained with a Chilean model 1895 long rifle in"7mm Mauser". cheers,FRosty.

    The same situation exists with the old Remington rolling blocks - the chamber specs were a bit different back then.

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    The .257 Roberts gauge is not correct for 7x57 Mauser. I got mine here: http://pacifictoolandgauge.com/metri...ce-gauges.html

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    Fireform a set of cases and assign them to this rifle. Of course, do not resize the full case.

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    I believe what is being described by Frosty is known as the Delta L problem. It is a CIP vs SAAMI thing. https://en.wikipedia.org/wiki/Delta_L_problem
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    Quote Originally Posted by qz2026 View Post
    The .257 Roberts gauge is not correct for 7x57 Mauser. I got mine here: http://pacifictoolandgauge.com/metri...ce-gauges.html

    Perhaps, it was ".275 Rigby" rather than 257 Roberts.

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    Quote Originally Posted by Frosty View Post
    i have been told of this headspace problem arising in this caliber,7mm Mauser,over the years. a good friend who happens to be a gunsmith of German heritage has described the situation as follows. the cartridge specifications given by the American SAAMI group are not the same as those used in Europe and so US mfg headspace gauges are different as well. the comments about this particular caliber,7mm Mauser,are always that the European chambers have excessive headspace when checked against US mfg gauges. regarding this particular rifle described on this page,there is a good possibility that it may work ok with "some" new ammunition. the Mauser extractor will only let the cartridge go a certain distance into the chamber when a cartridge is fired. if more stretching happens,it will occur at the cartridge shoulders at the front.
    i have owned and shot 4 or 5 of the same rifles as the one described here.used Canadian and American mfg cartridges and brass without any problems. problems may occur when using handloaded ammo with cases that were fired in different firearms. i've been collecting and shooting Mausers of all types for 35 years;the most impressive accuracy for me was obtained with a Chilean model 1895 long rifle in"7mm Mauser". cheers,FRosty.
    I planning on removing the wood, strapping it down to a table and remotely shooting a round out of it.

    Quote Originally Posted by Fal Grunt View Post
    Guess you better sell it to me

    Call Dave Manson and order a set of CIP gauges and check it.
    I will look into it. Thanks for the link!

    Quote Originally Posted by qz2026 View Post
    The .257 Roberts gauge is not correct for 7x57 Mauser. I got mine here: http://pacifictoolandgauge.com/metri...ce-gauges.html
    I was going by what was on the Forster's web page.

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    Well if these gauges that I'm using is incorrect, why do they work on my 93 Boer Mauser and my Oviedo Mauser? The Boer almost closed on a NO-GO and it did not close on a FIELD and the Oviedo did not close on a NO-GO. So if they are wrong ones, what is going on?

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    hi. don't forget that this rifle has been re-barreled with the SIG.this may have been done in Europe,and more likely may have been done in South America.more opportunity for different specs and gauges to be used. best to be safe,so your description of a test fire procedure sounds wise and safe.good luck,cheers.

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    The SAAMI chamber and cartridge drawing is page 43 at: http://saami.org/specifications_and_...FR.pdf#page=13

    The CIP drawings are at: http://www.cip-bobp.org/homologation...-en-page33.pdf

    The chambers are different and the SAAMI minimum is about .11 mm / .0043 in. shorter than the CIP minimum chamber.

    FYI standard Scotch tape is .002 in thick and you can add a couple layers to get a CIP gauge equivalent.

    And its supposed to close easy if the gauge is shorter than the chamber reference point, stop with a little click if longer. You do not want to force it ever - the slight squishiness from Scotch tape is an exception.

    I'm not overly cautious about headspace in any moderate pressure cartridges like 7x57. The only blowups I've ever seen are from overloads and the 1895 does have some gas venting provisions. You might wish to do a chamber cast. It's easy and even fun with Brownell's Cerrosafe. Then you can measure the chamber with a micrometer instead of depending on a gauge, and the Cerrosafe is reuseable.
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    Have you tested using a different bolt? A '93 may fit too, not sure.

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    You either have a excessive headspace problem or you are using the wrong ammunition. The "fix" depends on what is wrong! I suggest you take a unfired 7mm Mauser cartridge and insert it, bullet end first into the muzzle. If you have a 7mm rifle, the bullet WILL NOT entirely enter the muzzle to the case neck. If it does enter all the way, you likely have a odd caliber rifle as the 7,62mm Nato round is shorter than a 7mm Mauser. It may be in 8mm Mauser as I have encountered that combination. Look at the floor plate. If it is bulged or domed and not flatish, it may be a Turk kind of conversion. If you have a 7mm Mauser caliber rifle, musketshooter is correct. The fix would be to set the barrel back exactly 1/12 of an inch (Mauser threads are 12 to the inch.) by removing metal from both the chamber end and the shoulder. You need not remove the sights. Once reinstalled, everything is right back where it should be and the chamber will be shallow and will need to be carefully recut to the correct debth.

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    I have some spare SJG barrels that are in 7.65 Arg. I believe they were made for the Peruvian 1891 Arg. rifle as they have the correct O.D. at the muzzle for that kind of sight. I doubt that your barrel is one of these, as again the 7x57 is longer than the 7.65x53, but I suppose most anything is possible with a re-barreled rifle. One other possibility is that the rifles' lug shoulders have been set back by an excessive load or partial obstruction at some point in time, perhaps prior to its needing to be re-barreled?
    If it is indeed chambered for 7x57 and the headspace is just a little bit long, I'd not be bothered by firing factory ammo in it, as long as there were no apparent case stress issues, and as long as you are not planning on doing any reloading of the used brass for other rifles.

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    Your gages are for commercial 7x57 Mauser which was standardized in 1920. Before 1920, the cartridge was called 7mm Spanish Mauser and was widely sold to central and South American countries. 7mm Spanish Mauser rifles, will chamber and shoot 7x57 Mauser ammo. Many military rifles have generous chambers, sometimes due to decades of rough service, loose specifications so the rifle would operate in mud and dusty conditions, etc. Gages are really designed for modern sporting rifles made to tight specifications. You could remote fire the rifle and check the fired case for problems, or start with mild hand loads and work your way up. I have no worries of modern 7x57 Mauser ammo in my M1910 Mexican Mauser, but I use only cast bullets in my 7x57 Remington rolling block.

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    Measure the exact head space. Take an unfired round and load it, close the bolt. Then open the bolts and put a layer of tape on the back of the round, trimmed to fit the case. If it closes, add another layer. Keep adding layers until it closes but is really hard. Then pull the tape of and measure its thickness. A chamber cast is a good idea as well, to confirm it is the caliber you're expecting.

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    .257 Roberts was developed by necking the 7x57 Mauser to take .257" bullets. Would have to dig out something with chamber drawings to be sure, but I am pretty sure the shoulder location and angle were not changed, so a .257 Roberts gauge would probably work fine in a 7x57 rifle. which would explain why Forster says what it does.
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    Yes to the above...and 275 Rigby really is 257 Bob.
    243/7mm-08/308!!! same...
    It takes a Significant difference in headspace to have an effect on Reloaded Brass even.
    Excessive headspace does Not "blow-up" guns!!
    Chambering the wrong round??? No Blow-up, but some Eye-opening. Think about the Guy touching off a 308 in his 30-06!!!! Ya think the Headspace was excessive????
    It behooves collectors to be able to identify the Cartridge their Piece is Chambered for..
    Ignorance is not Bliss...Heck even canning wax works...I have done it...gives one an idea what is in there!!!
    Not rocket science here!!!

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    Cool

    The important issue from a safety standpoint is not how the gauges fit, but how the ammunition fits. It's the difference between chamber headspace (which is basically a theoretical measurement) vs. cartridge headspace (which is a practical, operational measurement that is specific to the particular ammunition you are actually using).

    Buy some Privi Partizan, Norma or other European-made ammunition made to CIP drawings and use that to establish a baseline measurement for your rifle. Chamber this round and feel how the bolt closes. Add shims between the bolt face and base of the cartridge, trying each time until resistance is felt GENTLY closing the bolt. Then measure the accumulated thickness of the shims with a micrometer.

    Headspace tolerance of rimless cartridges in the 7mm-8mm-.30-06 class is generally about ten thousandths between minimum & maximum chambers; theoretically one could have a minimum cartridge in a maximum chamber with room for about .010" in shims and still be within specifications.

    If you have more clearance than that, you have an overly deep chamber, or set-back locking recesses in the receiver (which can be examined with a dental mirror), or the bolt is haywire, or you are cranking down too hard on the bolt handle (by really leaning on it, you can make almost any rifle swallow a Field gauge). Before I pulled out the barrel I would certainly try another bolt.

    Thereafter, use THAT ammunition, and you'll be fine. If you change to a different brand of ammo, run this drill again.

    Incidentally, there is no need to remove the stock for test firing if you feel the need to do that. I've tested many military rifles by padding the buttstock with a small blanket, inserting the butt inside an old tire, tying it all down with rope, and firing with a lanyard.

    Fire a few rounds and carefully inspect the inside of the fired cases under a strong light. If you can't see, or feel with a wire probe, any sign of case separation, the headspace is good enough to be safe.

    M
    Last edited by MGMike; 03-02-2017 at 09:09 AM.

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    ^^ All good, but, I doubt you will see/feel/find incipient head separation in one Shot!!
    Reloading with FL sizing and repeated firing will show signs of Incipient head [case] separation..

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    Quote Originally Posted by Racepres View Post
    ^^ All good, but, I doubt you will see/feel/find incipient head separation in one Shot!!
    ...
    On the contrary. --Learned from experience.

    In any event, if one can't "see/feel/find" incipient separation, why worry about headspace? What problem does bad headspace create other than the risk of case rupture?

    I am always amazed at the fixation on headspace by some owners who blithely don't bother to thoroughly examine their guns for mechanical defects that often pose far greater hazards. A surplus rifle of unknown history might have perfect headspace, but be unsafe to fire.

    M

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    Here is what I did. On the 1893, 1895 and the Ovideo, I took the firing pin out of the bolts and chambered a Prvi Partizan round. All three closed with no resistance. I do not know if this is normal but that is what I did. I did not use the tape method like mentioned above. Maybe this weekend when I get a chance, I will try that method.

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    Click image for larger version. 

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    Incipient case head separation. You can make a feeler out of a bent paperclip to check for it.

    And BTW, safe headspace clearance is not a firm, hard number but varies depending on the strength and dimensions of the case and those will differ by manufacturer. Also see any article on the .308 vs 7.62x51 differences.
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    One can also use a little "catheter" light that will fit down inside the fired case, and clearly see the shadow of any stretch ring. I made one from a pen-light, some telephone wire and a miniature bulb from Radio Shack. It also will fit into the chamber to illuminate any flaws. With long enough wires, it can be drawn slowly through the bore to observe pitting, etc.

    But, as jjk308 says, a bent paperclip also works very well to detect incipient case failure. Fire enough surplus ammunition through enough guns and you'll encounter it.

    M

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    I checked the chamber with a bore light. I cannot see any imperfections or anything that would throw up a red flag. I'm hoping this Sunday I can get a chance to fire it if not it will be next weekend. I will definitely post the results and pictures of the fired casings or anything else that I discover.

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    If you are unsure of the Chamber...Just take a reprimed case, put 3 or 4 grains of bullseye in it...fill with Cream of Wheat, cap with Wax plug...
    Fireform over the Pond to feed the Fish...and inspect the resulting case...

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    So today I had a chance to fire the Chilean and the Boer War Mauser. I fired 10rds in each using PPU. All the cases formed perfectly from what I can see. No cracks, excessive bulging or any issues with the primers. Both of the rifles' bolts opened no problem, actually the actions on them were like butter with no resistance at all. I have pictures attached. The spend casings with numbers on them are the Chilean the other the Boer.

    Click image for larger version. 

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    Was that the 139 grain soft point in the blue box that you shot?

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    srv1,

    One other favor to ask. Does your Boer Mauser have a catch cut in the cleaning rod like the one in this picture?
    Attached Thumbnails Attached Thumbnails cleaning rod 3.jpg  

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    Quote Originally Posted by JoeACTM View Post
    srv1,

    One other favor to ask. Does your Boer Mauser have a catch cut in the cleaning rod like the one in this picture?

    No it does not and mine matches the rifle.

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    Picture 3, the cases that are numbered. Look at the shoulder on them. There is something "wrong" with the shoulder. Depending on the gauges you used, this could be why they failed headspace. Otherwise the cases look OK. Chamber is cut a little large, given the expansion ahead of the case shoulder. (web). Given that they were chambered in the 1890's, tolerances and machining were not quite what they are today, I would shoot them until my shoulder hurts. Clean well, oil, and put away till next time.

    edited to add, if you are really curios, buy a 7x57 case micrometer, and measure the cases. You'll know then just how out of spec your chambers are.

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    Quote Originally Posted by Fal Grunt View Post
    Picture 3, the cases that are numbered. Look at the shoulder on them. There is something "wrong" with the shoulder. Depending on the gauges you used, this could be why they failed headspace. Otherwise the cases look OK. Chamber is cut a little large, given the expansion ahead of the case shoulder. (web). Given that they were chambered in the 1890's, tolerances and machining were not quite what they are today, I would shoot them until my shoulder hurts. Clean well, oil, and put away till next time.

    edited to add, if you are really curios, buy a 7x57 case micrometer, and measure the cases. You'll know then just how out of spec your chambers are.
    I did not see anything that I thought that it would be dangerous to shoot. I should compare the two rifles brass to each other and see where I'm at. The Boer war passed but the other one did not but thanks for pointing that out for me. I learn something every day.

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    One last point on using the .257 Roberts headspace gauge. The Roberts round is very similar to the 7mm Mauser round. The difference that I saw was the thickness of the rim on the two cartridges. The 7mm Mauser is .050. The Roberts is .0473. As a result, in many cases, the bolt will close down on the .257 Roberts gauge on the older Milsurp chambers. Only happened to me on the Spanish guns for some reason. It seems you were successful firing the rifle. Unless you are going to collect many more 7mm's, it's probably not a wise investment to spend the money for a 7mm head space gauge. Glad it all worked out.

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