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Thread: 308 win in 1895 Chileno??

  1. #41
    Boolit Master


    Larry Gibson's Avatar
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    The information I've researched has the pressure measured in Europe back then during the development of the Mauser SR actions and the cartridges, including in Germany, as using the "bar" unit of measure. The figures were reported for the 7x57 in the development of the cartridge were for a MAP of 3900 "bar". That converts (1 bar = 14.5 psi) to 56,550 psi......? The 7.65 Argentine had the same bar MAP. The 6.5 Swede was 3800 bar (55,100 psi).

    And as I told you earlier EVPAT using a conformal transducer at the case mouth which give slightly less pressure than when measured a mid case body. Perhaps that accounts for the slightly lessor "peizo" measurement on your data sheets.

    Have you looked at the SAAMI and C.I.P. MAPs both CUP and transducer to actually see what the difference is?

    Larry Gibson

  2. #42
    Boolit Master
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    I have seen this 'discussion' over and over in various forums. Place near me had a converted Spanish mauser. So I asked about it not being that knowledgeable about such things. About half said it was junk, period, that a box of store bought 308 was asking for a trip to the hospital. I have yet to eat a bolt. Havent even tried to run store bought thru it. Only store bought I have is 20rd boxes of surplus for my CETME. Im not one to load to max to begin with. Its been digesting a diet of min to med 308 loads, with nary a hiccup.

    A quick look at wikipedia, some claim the info they put up is junk, maybe on the controversial or political stuff. But why would they screw with '7x57 mauser'? Factory 7x57 is listed as 51,000psi SAAMI or 56,565 C.I.P., not sure why suddenly 308 has to be kept to 46,000psi.

    Wikipedia does have this, which gives several testing methods to further confuse things.
    https://en.wikipedia.org/wiki/Small_...essure_testing

  3. #43
    Boolit Master
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    "BTW; here is the U.S. Army's specification sheet for the M80 cartridge right out of TM 43-0001-27"

    Notice the cartridge drawing on that page is of a .30-06 cartridge.
    I mentioned earlier that those manuals are full of such errors, which is why you should go to the source material , the propellant procurement data.

    " The psi measurement is in CUPs and is 50,000 not 48,000."
    I see nothing there about CUP.
    The entry gives a ball park figure, which is why much of the information in that manual is suspect.

  4. #44
    Boolit Master
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    "A quick look at wikipedia, some claim the info they put up is junk, maybe on the controversial or political stuff. But why would they screw with '7x57 mauser'?"

    If you look at the comment they made about the average working pressure being over 50 CUP using the very same Ordnance dept testing of captured 7mm ammunition they choose to use only the figures given for the obviously defective or degraded (split case necks for one obvious sign) French manufactured ammunition which greatly exceeded that of the German manufactured ammunition which itself showed obvious extreme variations in chamber pressure without corresponding increases in velocity. The German ammo, even with its extreme variations gave a average pressure of 48,600 CUP.

    Gibson
    "The information I've researched has the pressure measured in Europe back then during the development of the Mauser SR actions and the cartridges, including in Germany, as using the "bar" unit of measure. "
    German proof test pressures in the 19th century were in Metric Atmospheres which is the equivalent of BAR, but they did not use transducers because they did not have them to use.
    Any comparisions made would be apples and oranges.

  5. #45
    Boolit Master


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    I stated earlier that the 7,000 psi ES along with the 35 fps ES of the 10 shot test of the German 7x57 ammunition conducted in 1898 was well within the allowable ES variations of SAAMI, C.I.P. and military standards of today (our military ammunition testing conforms to SAAMI specifications). There was absolutely nothing about the German ammunition "which itself showed obvious extreme variations in chamber pressure without corresponding increases in velocity" that is out of the ordinary for many, many acceptable tests of commercial and military ammunition.

    You really should look at the SAAMI manual on their standards instead of relying on internet searches for misinterpreted information. Try going to the horses mouth for the straight information. None the less lets try this as one last stab at helping you understand:


    SAAMI CUP MAP for the 7x57: 46,000 CUP
    C.I.P. CUP MAP for the 7x57 : 49,000 CUP

    SAAMI transducer psi for the 7x57: 51,000 psi
    C.I.P. transducer psi for the 7x57: 57,000 psi

    The Ordnance Departments CUP measurement in 1898 of the German 7x57: 48,600. Last time I checked Germany was still in Europe in 1898 and would have to be adhering to European stands i.e. the C.I.P. MAP of 49,000 CUP. Obviously the German ammunition was within that standard.

    Now if the C.I.P. CUP MAP is 49,000 and the C.I.P. transducer MAP is 57,000 won't they be one and the same even though measured by different means? If the SAAMI CUP MAP is 46,000 and the SAAMI transducer MAP is 51,000 won't they be one and the same even though measured by different means? That being the case then my measurements of factory 7.57 ammunition and milsurp 7x57 ammunition as taken with the strain gauge are entirely in line with both SAAMI and C.I.P. transducer measurements.

    Larry Gibson

  6. #46
    Boolit Master
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    "The Ordnance Departments CUP measurement in 1898 of the German 7x57: 48,600. "
    Which is still a long way from the 50,000+ CUP claimed in the Wiki entry and higher than the working pressure found in the Mauser Oberndorf catalog.

    Look at the velocities of each round fired then compare the chamber pressures of those rounds. The powder was degraded, not to any great extent but degraded just the same by storage in a tropical environment which Cuba certainly is.

    The German 7mm tested was within reasonable limits but not to design specifications. The French ammunition the Wiki entry used as a basis for their claim most certainly showed shoddy workmanship and exceeded the pressures of the German cartridge.

    Average pressure is an average, not the highest or lowest of cartridges tested.

    "(our military ammunition testing conforms to SAAMI specifications)" not sure what you mean by conforms through apparently M118 LR is tested along the lines used by SAAMI. The M80 Ball is tested by EPVAT methodology and by the radial crusher gun. The CUP readings may be the same but the transducer methods are not, in part due to the necessity of establishing gas port pressures.

  7. #47
    Boolit Master


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    dam...now I've got a headache. I recall how my first wife would argue with a potato peel if she took a notion.........
    An old Cherokee was teaching his grandson about life. "Inside me two wolves fight," he told the boy.
    "One is evil - he is anger, envy, greed, arrogance, self-pity, resentment, lies, false pride, and ego. The other is good - he is joy, love, hope, serenity, humility, kindness, generosity, truth and faith. The same fight is inside you - and every other person, too."
    The grandson thought for a minute and asked,"Which wolf will win?"
    The old Cherokee replied, "The one you feed."

  8. #48
    Boolit Master


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    It is painfully obvious you've little or no experience measuring the pressure of any cartridge. It is also painfully obvious you've not bothered to read the SAAMI standards or really read the Wikipedia reports on the EVPAT pressure measuring. Our Ordnance Depart adheres to the testing standards and procedures of SAAMI. That includes CUP pressure measurement and transducer pressure measurement on the case body and at the case mouth. If you had read the SAAMI standards you would know it is for commercial manufacturers of which most of our military small arms ammunition are made by. You would also have found there is no SAAMI specification for the 7.62 NATO cartridges because those standards are under STANAG agreements.

    I have measured the internal ballistics of literally thousands of test round of 35+ cartridges. A measured MAP and a MAP standard SAAMI, C.I.P. or EVPAT are most often different. The standard MAP is what loaded cartridges should not exceed under standard test conditions. The measured MAP of any lot of ammunition is often different and often lower than the standard MAP. Once again, cartridges are loaded to a specific for the cartridge velocity +/- not to exceed the standard MAP. That does no mean they are loaded to the pressure level of the standard MAP. Had you read the SAAMI standards you would perhaps have understood.

    The fact that the German 7x57 ammunition tested in 1898 averaged 48,400 CUP and the Wikipedia MAP for the 7x57 says its 50,000 CUP is as it should be.

    A pressure variation of 7,000 psi ( the ES of the 10 round test string in 1898) is not bad at all and is absolutely no indication of powder degradation. Especially since the Ordnance experts who examined it found none. How you, 119 years later, without any personal examination of such can determine the powder was degrading based on what you assume to be an extreme ES of pressure is a stretch even for the internet. The ES of 7,000 CUP for a 10 round test string is quite acceptable especially considering the ES for the velocity was only 35 fps. All in all quite good even by todays acceptance standards. The German ammunition was well within "design specifications". No it was not loaded to the standard do not exceed MAP but then most lots of ammunition loaded then and loaded now are not either. Your error apparently is thinking all ammunition is loaded to the MAP for the cartridge.

    I am assuming also you mistakenly believe that in a test of the same ammunition that a slightly higher pressure always results in a higher velocity? That is not so as I have seen the reverse many times. I also have seen, many times in the same test string, psi's of 1000+ variation with but 3 - 5 fps difference. Should you actually delve into any actual pressure test results to SAAMI, C.I.P. or EVPAT standards you would see that. You could also ask any ballistician. They have all seen the variances too. Stating that such variations is caused by degradation of the powder belies your inexperience in such test matters.

    "(our military ammunition testing conforms to SAAMI specifications)" not sure what you mean by conforms through apparently M118 LR is tested along the lines used by SAAMI. The M80 Ball is tested by EPVAT methodology and by the radial crusher gun. The CUP readings may be the same but the transducer methods are not, in part due to the necessity of establishing gas port pressures."

    Yes, our M80 conforms to the STANAG specifications using EVPAT testing criteria. So who do you think produces our M80 ammunition? It is commercial manufacturers as we have not had government own small arms manufacturing for some years. Those commercial manufacturers use SAAMI test specifications conforming to the STANAG 7.62 NATO criteria of which EVPAT is a part. Where do you think SAAMI developed the test criteria, standards and specifications from? Take a hard look at that test conducted in 1898 and you'll see the beginnings.

    At any rate, you obviously refuse to consider other than you've gleaned and obviously misinterpreted off the internet. I've tried over and over to show you where to find the correct information. I've led you to the trough, it is up to you to drink or not. Have a good night.

    Larry Gibson

  9. #49
    Boolit Master
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    "The fact that the German 7x57 ammunition tested in 1898 averaged 48,400 CUP and the Wikipedia MAP for the 7x57 says its 50,000 CUP is as it should be. "
    Did you bother to read their reasoning for making that claim? They based it not on the average pressure of 48,000 CUP of the German ammunition but rather on the higher pressures generated by whatever off brand French ammunition was tested along side it. Did you bother to find and read the Mauser catalog entry on the Spanish Mauser and its ammunition. I've had my reprint which was published in Gun Digest in 1961 since I bought my second Mauser. The specifications for the 7mm are very complete and contributed by DWM.

    The Wikipedia claim of 50K CUP then exceeds the design pressure envelope of the 7mm Ball cartridge as manufactured specifically for the rifle when it first came out and the pressures generated in testing.
    The Mausers were proof tested at a higher pressure in order to take into account the known effects of degradation of powders stored in Tropical Climes. From reference works of that time period the Proof Testing of Military smokeless powder rifles were done using the Special Leaf powder which was a form of the standard "Leaf" or flake powder formulated to generate higher pressures at the same charge weight.

    The question was not how far out of spec off brand 7mm cartridges can get before the rifle is damaged, it was what pressure level the 93-95 actioned rifle was designed to digest.

    As the condition of many of the converted rifles and some still in the original chambering suggests a diet of cartridges that generate pressures beyond that of the designed specification does in fact damage the rifle though it may take many rounds fired before the damage becomes obvious.

    Its also obvious that that there are very good reasons why cartridges in storage are tested at intervals by lots and when any significant percentage exceed the stated maximum pressures the whole lot is condemned.

    If SAAMI and EPVAT testing are the same tell us what the gas port pressure standards for the 7.62 , the .308 or any other cartridge is going by SAAMI specifications. That should be easy enough.

  10. #50
    Boolit Master
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    Larry your wasting your time. Its alot of typing for no results, one would think this was the pit.

  11. #51
    Boolit Master


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    Tackleberry41

    You are absolutely correct, I'm not wasting any more time.....Multigunner just wants to argue, I'm moving on.

    Larry Gibson

  12. #52
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    Yep, probably best to put this one to bed.

    My take on the original topic of small ring Mausers is that maturing designs (91, 93 & 95) don't improve with age and steel doesn't get stronger with age. Having seen older Mausers with lug set back, I'd be inclined (if I had a 95) to just load it down and enjoy it. I do that with my SR Argentine Model 91 Mausers and enjoy them immensely.

    Lots of good info in the thread though. I appreciate that.
    Last edited by Scharfschuetze; 03-17-2017 at 11:21 AM.
    Keep your powder dry,

    Scharf

  13. #53
    Boolit Master


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    Scharfschuetze

    Couldn't agree with you more. The jacketed loads I use in my own SR Mausers of various original cartridges I keep at or below the C.I.P. MAPs and mostly below or at the SAAMI MAPs. Doing that has nothing to do with what the original loadings of the cartridges actually were. Those I've found are most often just +/- the C.I.P. MAPs. In post #15,http://castboolits.gunloads.com/show...sh-Mauser-7x57 I list several of my favorite 7x57 loads I use with jacketed bullets in my M95 and other M93s and M1916s that have come through my hands. I've become especially fond of that listed 175 RN load, amazingly accurate and, I'm sure, would be quite deadly on game.

    Larry Gibson

  14. #54
    Boolit Master
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    Scharfschuetze
    Well Said!!
    While I have One 7X57 that is Not a SR Mauser...I shoot it very Little..My '93 gets a Serious Workout...Tho my '95 is More accurate...
    I do Not Custom Tailor loads...I load "By the Book" Cast Boolit loads, and Enjoy immensely.

    BTW I have yet to load any 7X57 with a Boolit/J-Word, heavier than 140 gr!!!!!!
    Flame On!!!!!!!!


    Darn!!! Edit to get on Subject...my CETME 1916 [308] has digested a gajillion 150gr Boolits with 12 gr of Unique under them...Hasn't missed the Swinging target, nor Stray Critter...yet...Scout scope HomeMade mounted quite a few years ago...
    Last edited by racepres; 03-17-2017 at 03:42 PM.

  15. #55
    Boolit Master


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    Here's my Oveido M1916 (Made in '28) I built back in '68. I got just the complete action for $8. Put it into a Richards Micro-Fit stock and put a Star 26" sporter barrel on it chambered in .308W. You can see the stock is cut out where I had put a Lyman 48 Long Slide receiver sight. I made a front sight base for an M14 front sight. It has a Dayton/Traiser trigger and was converted to cock on opening. I shot that first Star Barrel out and put another one on it also chambered in .308W. Shot over 10,000+ rounds of US M80 Ball and along with one can of XM118 and a couple cans of M118 through those two barrels along with some hellacious .308W handloads (were max loads in older manuals) which proved out to have mid 60,000 psi's. That rifle has accounted for numerous deer, a couple elk, who knows how many coyotes, untold number of rock chucks and jack rabbits.

    After the second barrel was shot out in the late '70s I pulled the barrel and found minimal lug set back of .001 - .002" maybe. I had a new two groove 'A3 barrel and had it set back and rechambered to a cast bullet cartridge of my own design; the .308 CBC. That's what it is today.

    Click image for larger version. 

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    Here's the M95 Chilean 7x5 I use for pressure testing.

    Click image for larger version. 

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    Larry Gibson

  16. #56
    Boolit Master
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    Wondering now how to "clean up" the bit of frosting evident in my Chileno's barrel--I cleaned and cleaned it and the cleaner it (bore) got the worse I looked! By the time patches quit coming out blue/green, they were coming out clean but kinda roughed-up--the bore felt kind of "grabby", so I thought I'd try shooting some jacketed thru it and clean it up after every few rounds.

    Accordingly I bought a few hundred 174 gn Privi FMJBT bullets from Powder valley--Loaded up 50 and shot them over 41.2 gns of AA2700 and went back to cleaning with Wipe-out foaming cleanser. Seems to be working out; how much of this do you think I'll need to do to get to the point I can shoot boolits without too much leading? The I've gone up to 42.5 gns of 2700 and plan on cleaning after every 10 rounds--fired 5/cleaned yesterday and the bore is starting to look kinda shiney.

    Do you think 42.5 gns is too much? Primers look OK but I don't want to abuse the old girl; I planned to shoot only boolits but the grabby bore condition made me think twice about that!

  17. #57
    Boolit Master
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    I've heard of a condition called a "hairy bore" where thermal alligator cracking of the surface turns up at the edges like dried mud flats. Fibers from patches catch on the rough edges leaving a fuzzy hairy look when you look down the bore. Its mainly found in very old milsurp rifles that have fired thousands of rounds of cartridges loaded with high nitro content double base powders. More modern barrel steels aren't as affected by this thermal cracking. Some modern barrels are nitrided in manufacture to head off the situation before it starts.
    I only remembered it because the first time I heard of it was in relation to old Boer War Mausers.
    I've seen this a few times in the past but didn't know what caused it till a few years back.

    If it is thermal alligator cracking the bore surface will be many times harder than whats underneath and brittle, sooner or later the brittle scales break away.
    Hardened carbon fouling infiltrating the edges of the scales is what turns the edges up and to some extent stabilizes the surface.
    You'll probably have to have the bore lead lapped to get rid of it, and that may not work, and if it did the bore would be enlarged.
    Fire lapping might work, probably worth a try.

    Anyway that's the only thing that comes immediately to mind, it may be something else entirely.

  18. #58
    Boolit Master
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    My one Large ring Mauser 7mm barrel is about a sewer pipe...but..better than it was when I first got it. I did shoot a 1916 7mm clean[er] it came around pretty good..and now gets only cast [oversize]. I am thinking I will try Paper patched smokeless loads in the '98...see if it shoots clean.

  19. #59
    Boolit Master


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    Quote Originally Posted by racepres View Post
    My one Large ring Mauser 7mm barrel is about a sewer pipe...but..better than it was when I first got it. I did shoot a 1916 7mm clean[er] it came around pretty good..and now gets only cast [oversize]. I am thinking I will try Paper patched smokeless loads in the '98...see if it shoots clean.
    Might try fire lapping with cast that fit the barrel. I have smoothed out several milsurp barrels that still had strong rifling. They all shot fairly well with cast afterward. I have the old fire lap kit that is now sold by Wheeler(?). some grits of valve grinding compound can also be used successfully. Easy to do.

    Larry Gibson

  20. #60
    Boolit Master
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    Quote Originally Posted by Larry Gibson View Post
    Might try fire lapping with cast that fit the barrel. I have smoothed out several milsurp barrels that still had strong rifling. They all shot fairly well with cast afterward. I have the old fire lap kit that is now sold by Wheeler(?). some grits of valve grinding compound can also be used successfully. Easy to do.

    Larry Gibson
    yes I know about that...even have done it..Handlapped as well..This time, I wish to try the Paper patched in order to satisfy my curiosity. Paper patched barrels sure look ...Shiney!!!
    and I don't think the dimensions are changed to extent that Firelapping changes the throat. But
    IDK

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