Looking at a Chileno on GB seller claims it's in 7,62x51?? Were any Chileno mausers 7,65x53mm?
Would this even be safe in the M1895 action?
Looking at a Chileno on GB seller claims it's in 7,62x51?? Were any Chileno mausers 7,65x53mm?
Would this even be safe in the M1895 action?
They were rebarreled or rebored to .308 or the CETME 7.62x51. They were originally 7x57. Some say they're safe and some don't. I would treat it like the action is 100 yrs old and reload to the design pressure. All the 95's I believe are German so that helps.
I am not an old fart. I am a nefarious curmudgeon; an old fart with an extensive vocabulary and a really bad attitude.
Great post Skipper. I revise my advice to rebarrel that action to a small ring certified cartridge. Lots of great choices but hard to ignore the original 7x57.
Skipper, thanks for the link! The pix of the "El Supremo" make me drool!
I decided to pass on the "308" Chlieno Mauser as I could not fathom the 308win in the 1895 action--from what I gathered reading the Dutchman's info, the original 7x57 barrels were rechambered to 7.62 Nato? With a 7mm bore?
I have a Chileno in 7x57 and love it the way it is--bore is kinda frosty but I'm workin' on it. Got it from a member here and the wood looks plain but very clean and nice.
I bid on the rifle in question before I noticed it was stamped "7,62" on the reciever bridge (also the seller said it to be "308 winchester") and I failed to notice that too.
I have passed the link supplied in post #3 to the seller with advised him to caution the buyer against shooting commercial 308win ammo(or anything not severely down-loaded!).
Said it many times but...
I have been shooting my CETME Spanish 1916 [model '93 small ring] for years...
I handload Only, and I use approximate 300 Savage loads..
While I love the 7X57 Many folks will tell you that 300 Savage is OK, or even preferred...
I like the CETME with Savage loads because it has a Longer neck, and I prefer Cast lead Boolits!!!
But...For Factory loads....You should Pass!!!!
"from what I gathered reading the Dutchman's info, the original 7x57 barrels were rechambered to 7.62 Nato? With a 7mm bore?"
They rebored the barrels to 7.62, but due to the 7X57 being a longer case they had to bore the front of the chamber deeper to accept a chamber adapter similar to the operation used by the USN to convert .30-06 Grands to 7.62 NATO.
The chamber insert is just soldered in place and sooner or later the adapter develops problems due to gas cutting of the soldered joint.
NATO M80 Infantry Ball is not a very high pressure cartridge, only 48,000 CUP, but M118 and similar Special Ball and Long Range cartridges generate much higher pressures unsuitable for the small ring Mausers. M118 generates pressures very close to the 58,000 CUP proof test loads used for the 1888 Commission Rifle and the early Small Ring Mausers. Some Long Range Match loads for the .308 exceed the pressure of the proof test loads.
First of all let me say I'm not accusing anyone of lying.......it is the point of the quote I'm making.
M95 Chileans were converted to 7.62 using two methods; first was, as the link to Dutchman's article shows, was by drilling out the 7x57 chamber and solder/brazing an insert in it, reboring and rifling the barrel to 7.62 and then rechambering to 7.62 NATO. This was not a safe conversion. However the second method was to rebarrel the M95s with a new 7.62 barrel. Those conversions are safe to use with .308W and 7.62 NATO.
Unfortunately Dutchman repeats data, by quoting other sources, attempting to show that .308W generates a lot more pressure than 7.62 NATO. The data he gives is essentially correct but it is misleading. The SAAMI MAP for the .308W quoted (62,000 psi) is that. The U.S. Military spec MAP quoted for the 7.62 NATO is 50,000 psi. So what is misleading about that? It's apples vs oranges; the SAAMI MAP for the .308W measured with modern transformal peizo-transducers. The psi MAP for the 7.62 NATO is from 1950s Copper Unit Crusher (CUP) psi measurement. If we look further into SAAMI information we find they also list a CUP MAP for the .308W. It is 52,000 psi.
Thus in reality we have very close MAPs of 50,000 and 52,000 psi with both measured by the same. I have measured the psi of numerous U.S. and foreign 7.62 NATO cartridges and numerous .308W factory rounds and find the actual lot to lot MAPs of .308W and 7.62 NATO overlap so much it is almost impossible to say which actually has the higher psi. Just this morning I measured the psi and velocity of my reference lot of M118 SB. It ran it's usual 61,000 psi +/-.
This brings us to another untruth told so often every one believes it; "Mauser designed the SR actions for 45,000 psi".....Problem with that is Mauser did not measure "psi"s and even the CUP method of chamber pressure measuring was not in use then. Mauser designed and made the SR Mauser actions as strong as he could given the metals and technology of the day. Cartridge design was in it's infancy and cartridges were loaded to be safe in the actions they were made for. So where does the 45,000 psi come from? Darned if I've been able to track it down, that statement has been repeated so often it's become the "truth". What I do know is I have measured the psi of numerous milsurp cartridges made for SR Mausers (6.5 Swede, 7x57 Mauser, 7.62 CETME, 7.65 Belgian and 7.65 Argentine) dating back to 1918 (Spanish made 7x57). They all had MAPs of 53 - 60,000 psi. European factory loads for the same cartridges have essentially the same MAPs as their milsurp counterparts. Seems to me there would be a lot of blown up SR Mauser rifles if they were "only safe for 45,000 psi". I've yet to find a milsurp 7x57 the generates less than 51,000 psi.
I have found several non NATO spec 7.62 cartridges that generates 45,000 to 53,000 psi for use in those countries with HK M91s and for one country that had FN-FALs.
Another "truth" that has been told so often about the FR7 and FR8 rifles is they were "designed for the 7.62 CETME cartridge". I'm sure you've all heard that one as it is repeated often on this forum. We all know the 7.62 CETME is a low pressure load to be safe in those rifles which were only designed for 45,000 psi.....right? Well I happen to have come across a quantity of original Spanish made in 1962 7.62 CETME ammunition. I pressure tested it in the same test rifle I shot the M118 SB in this morning......guess what the 7.62 CETME's MAP was? Well it wasn't below 45,000 psi and it wasn't 300 Savage level either.....it was 60,000 psi for a test string of 10 cartridges (I will post the Oehler data sheet for the non believers if they'd like?). Yes, I know we have been told over and over again the CETMA cartridges had lower pressures that the 7.62 NATO. Problem is they don't....the German engineers who came up with the CETME cartridges to solve the extraction problems in the then unfluted chambers of the CETME rifles altered the time/pressure curve with a faster burning powder and were able to maintain the recoil impulse to function the delayed roller blow back action of the CETME rifle by using a lighter weight bullet and redesigned rollers. The actual operating pressure of the ammunition had to remain the same for the CETME rifle to function. But we have been told over and over again that the FR7 and FR8s, regardless of what the Spanish manual for those rifles says, are not safe with 7.62 NATO ammunition but only with 7.62 CETME psi level ammunition.......since they are the same psi level is there really a difference?
I recently came into some actual Chilean 7x57 cartridges they made for use in their M95s. The armory they were made at in Chile is over 200 years old and still is producing quality arms and munitions btw. I will be pressure testing it in my own M95 Chilean 7x57 next week and will report the results......should prove interesting.
Last edited by Larry Gibson; 03-13-2017 at 05:42 PM.
Is there any way to tell whether a rifle has been re-barreled or re-bored and chamber plugged? Without breaking it down?
Glad I passed anyway--gun went for $205 ++
"even the CUP method of chamber pressure measuring was not in use then"
Are you sure of that?
The oldest copy of W W Greener's book "the Gun and its development" that I've found so far mentions the CUP method in use by Germany at that time. The Copper Units method was a French invention. CUP pressures were converted to Metric Atmospheres, same as the British BAR designations. Both Metric Atmospheres and BAR are easily converted to CUP or PSI according to the method used in testing.
Greener explains the German method of establishing Proof Test pressures based on the expected pressures of degraded ammunition fired in a very hot tropical climate. Rather than increasing the powder charge, which reduced capacity, they formulated special powders that mimicked degraded powders.
The USA was still using a method where a steel chisel headed spike was driven by chamber pressure into a block of copper. The penetration of the spike was measured to get a pressure reading. That method is so antiquated that I've never found much about it.
An account of the Gran Chaco War tells of older small ring actioned rifles failing when 1930's ammunition loaded for 98 actioned rifles and MGs was used in the older rifles.
By 1915 DWM was manufacturing a cartridge intended for 98 actioned 7mm rifles that launched a 154 gr bullet at over 2900 FPS. I doubt very many 93 or 95 actions could handle those.
Years ago I ran across accounts of testing of captured Spanish American War era 7X57 ammunition, including attempts to develop an identical load using American made smokeless powders of the day. I don't remember there being much in the way of modern pressure levels in those tests.
As for US Army ammunition technical manuals many contained bad information and were constantly being updated and revised. The best source for chamber pressure specs of the various 7.62X51 NATO cartridges is the propellants procurement data sheets. These give allowable pressure ranges in both CUP and PSI EPVAT except for M118 Special Ball which is expressed in CUP only.
Yes I am sure. The CUP method was also in developmental stages along with smokeless powder cartridges (also in ther infancy and early developmental stages) and their higher attendant pressures in the 1880s and 1890s. The basic method of CUP pressure measurement used for the next 100+ years did not come into general use until the mid/late 1890s after several articles appeared in a couple of the scientific journals of the day (they can be found through google). Refinement of the CUP system wasn't complete until after the turn of the century. Note cartridge case development and refinement continued to have safety issues through the early 1900s. It was those issues that prompted many of the safety features found on the M98 action that aren't on the SR actions.
Mauser had the basic design of the SR actions completed by 1888 and the M92/M93s were produced in those years meaning they were developed before then. The M95 and M96s were refinements of the basic SR action as better steels and heat treatments were developed. It was not the design of the Mauser Actions that held pressures lower in the early smokeless cartridges but the powders and case itself. It wasn't until newer more consistent powders were developed along with brass and case manufacturing technology over the next century and even continues today that the higher magnum level of pressures became containable. However, the Mauser actions were quite able to contain and maintain service capabilities with cartridges of 50,000 CUP psi (60-62,000 psi as measured with transducers).
We hear lots of tales of "machine gun" ammunition loaded to higher psi. Yes there were a few documented cases of that. However, military ammunition packaged in boxes of 15 rounds (the amount per ammo pouch commonly used) in 5 round Mauser stripper clips was intended for Mauser rifles, not machine guns. The 1918 Spanish made 7x57 cartridges I tested had the 174 gr cupro nickel RN bullets and were in stripper clips. The European C.I.P. MAP for the 7x57 is 57,000 psi (transducer). The 1918 ammo ran a psi of 56,500 in my M95. I also tested some of the 154 gr so called machine gun loads and they did run a little hotter at 59,400 psi. Even Remington and Winchester factory 175 RNSPs exceeded the SAAMI MAP of 46,000 psi (transducer) running at 47,900 and 49,900 psi. Checking my records I did find 2 loads that did not exceed the SAAMI MAP; one commercial and one milsurp. They were Hornady's Light Magnum and Venezuelan CAVIM 7x57.
As I said it will be interesting to see what the Chilean made 7x57 will run out of a M95 as that's the rifle it was made for.
If using the NATO EVAT pressures listed for 7.62 NATO ammunition it is also a apples vs oranges comparison with SAAMI or C.I.P. pressures as the EVAT transducer measurements are taken at the case mouth not the middle of the case body as are the other two. Still those are much closer and a more valid comparison than attempting to correlate CUP measurements with transducer measurements. The EVAT MAP (they call it a MPa/psi) for M80 ball is 60,190 BTW.
It is an incorrect assumption to believe every cartridge is loaded to the MAP. It isn't done that way. Most military and commercial cartridges are loaded to a velocity/accuracy standard (surprisingly there is a rather large +/- to that standard) while maintain less than the established MAP. Some, given the nature of the lot of powder used, are close to or at the MAP. Newer modern ammunition, given the unforeseen variable the ammunition will be used at, the actual pressures the ammunition is loaded to is usually less than the MAP giving a "fudge" factor. However, in days of old pre SAAMI and CIP many were loaded to maximum pressures for the cartridges, even those for use in SR Mauser actions.
Last edited by Larry Gibson; 03-14-2017 at 11:11 AM.
Let's not forget all the 1893 Turk 7.65s converted to 7.92x57. They seem to hold up.
And all the Turk '30s, '40s and '50s milsurp I've pressure tested has been in the 56 - 59,000 +/- psi range. Same as German pre and WWII era 8x57 milsurp.
Well now we know why so many 93 and 95 Mausers are found to have serious lug setback.
I think the point being made is that a good shape SR will hold up to .308 pressure levels but not a good idea for a steady diet. After all we want that action to last another hundred years.
No, M93s and M95s probably should not see a steady diet of any loads that go over 60,000 psi (transducer). Personally I keep jacketed bullet loads in the 54 - 57,000 psi range for use in my own SRs (M91s, M93s, M95s and M96s). Of course normal cast bullet loads and even HV ones won't get anywhere near that psi range.
As to lug set back we seldom know the real firing history of such actions. Prior to obtaining the Oehler M43 I had several "excellent" loads worked up years ago for several cartridges (.223 Rem, 6.5-280, .308W and 30-06) using the old methods proffered in loading manuals and in magazines. All but the 6.5-280 were within recommended loads in those older manuals. The 6.5-280 load with H4831 under a 129 gr Hornady was generating over 67k psi. After 2,000+ rounds of that load the lugs in a M98 Mauser had set back .001 - .002". I have seen several M93 FR7s with some lug setback. After discussing the ammo used while they had shot a lot of 7.62 NATO (U.S. M80 ball) they ad also loaded max .308W loads out of manuals (none had bothered to work up loads) and shot quite a few.
The .223, .308W and 30-06 were pushing 64 - 68k psi! It's why I suggest most reloaders stay within loads of the newer manuals that adhere to SAAMI MAPs. Those with wildcats or with a lot of experience may venture outside of that parameter if they have firearms made for higher pressures chambered in older cartridges such as the 45 Colt, 35 Remington and 45-70, etc. When doing so great care should be used along with a chronograph. No, the chronograph will not tell you the pressures but if you find velocities higher than expected then there are attendant higher pressures.
As when the use of CUP pressure measurement came into general use (as we know it) and what pressures Mauser may or may not have designed his actions for I have researched it for many years. What I found is basically stated in the previous post. However, should anyone have other documented information I would certainly like to see it. I am always learning and am very will to change my findings when new facts are found.
Here's a Report to the Chief of Ordnance 1898 on testing of captured Spanish Mausers and the 7X57 cartridges captured in Cuba.
In attempting to duplicate the ballistics of the French and German manufactured Ball cartrdges, using the cartridge cases and bullets of the respective origins but the charge replaced by the then current Dupont manufacture No 9 Smokeless powder, they found the Dupont powder generated less chamber pressure and less variation in chamber pressure.
German cartridges varied in pressure from 43,200 CUP to 51,150 CUP, with only 39 FPS difference in velocity between the two. The French cartridges varied from a low of 48,250 CUP to a whopping 55,800 CUP with the lower pressure giving the higher velocity of the two.
When loaded using Dupont No.9 powder the chamber pressures did not exceed 42,100 CUP with a low of 35,450 CUP.
Thanks for the inclusion of that information. I have read and studied that report and some similar ones from the same time period. It and the others were the basis for my statement; " The basic method of CUP pressure measurement used for the next 100+ years did not come into general use until the mid/late 1890s after several articles appeared in a couple of the scientific journals of the day (they can be found through google)".
Noting the 43,200 CUP to 51,150 CUP of the tested German 7x57 ammunition which was what the Mauser SRs (M92, M93 and M95s) were made to use we see a good correlation to the MAP of 50,000 CUP for the 7.62 NATO. Those German CUP psi's also conform to the transducer psi measurements of 50,000 to 60,000 psi that I have measured in the corresponding milsurp 7x57 and 7.62 NATO cartridges. Note the test report stated no damage was done to the Mauser rifles which I assume to be M93s, probably captured in Cuba.
|BP||Bronze Point||IMR||Improved Military Rifle||PTD||Pointed|
|BR||Bench Rest||M||Magnum||RN||Round Nose|
|BT||Boat Tail||PL||Power-Lokt||SP||Soft Point|
|C||Compressed Charge||PR||Primer||SPCL||Soft Point "Core-Lokt"|
|HP||Hollow Point||PSPCL||Pointed Soft Point "Core Lokt"||C.O.L.||Cartridge Overall Length|
|PSP||Pointed Soft Point||Spz||Spitzer Point||SBT||Spitzer Boat Tail|
|LRN||Lead Round Nose||LWC||Lead Wad Cutter||LSWC||Lead Semi Wad Cutter|