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Mauser used a different carburizing compound inside the lug recesses than on the outside of the action. I would bet if you sectioned the receiver and tested the lug surface it would be harder than the bottom flat. However I'm not offering my own receiver to cut in little pieces for this testing. | |||
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Out of curiosity what should the hardness be? I have an FN that is as hard a my head. It has many hardness testing divots right where you show. | |||
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Interesting post. Thanks. Life itself is a gift. Live it up if you can. | |||
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Ha; the encyclopedia is in my head, and much of it I make up as I type. Interesting post; some interesting data. How hard is hard, and how hard should they be? First, you can't really test where it counts, on the lug recesses, as stated above. So I guess on the outside bottom is as good as you can get. Secondly, you can't compare any alloy steel part to a carburized one. Thirdly, how hard should a Mauser be? Somewhere between RC 30 something and 60 something more or less. But since you don't know how deep the case is, all that is irrelevant. And if you had a chrome moly or nickel steel one, it might be soft as butter and still be ultra strong. Like the last 03 springfield (Nickel) and any modern rifle (chrome moly). The data shown above is pretty much what you would expect. When I send them out for heat treat, I specify a hardness of RC 35-40 and a case depth of 10-15 thou. That insures that they won't get brittle. | |||
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Anyone have a bad or dangerous experience with an action that was too brittle, just curious? | |||
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Exactly; it is the genius of design, not the steel, that is important. Ok, the steel is fairly important, but obviously can, and does, vary all over the map, so to speak. Experience with a brittle one? No. Hard ones? Yes. 1917 Enfields are sometimes too hard to drill, and are very thin in the ring; I spot anneal those. Mausers, usually if you can get through the case they will drill. You will find the 1909 soft. Ish. Relatively. Not that that is a bad thing. | |||
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Very interesting. Yield strength correlates with hardness. Typically and if modern action and barrel made from AISI 4140 chrome-moly steel here's about how for reference only not for design -  | |||
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Yep and that Ruger at 48Rc is about 200,000 psi yield strength and Mauser made of 1030ish steel about 40,000 psi yield. As far as Mauser's strength through design, well maybe compared to inferior designs of past eras. But if you are comparing 2 lugs in 2 lug seats with basically the same square inch areas in shear (Mauser vs Ruger, Rem, Winchester, etc) a Mauser made of low carbon steel is substantially lower in strength. If I recall Johannsen claims their 98 actions made of 42CrMo4 (+/- 4140) are 4 times stronger than the original Mauser. Which seems about right. | |||
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Do not forget the fact that there are millions of Mausers out there that show no signs of wear; yes they are weaker than modern actions made from 4140. But, how strong do they need to be? Calculate the back thrust and you will see why they have lasted so long and are in no danger of extinction. | |||
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Just looked up the specs on 1030, when hardened to 22RC it has a yield strength of 90,000 PSI not 40,000. | |||
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The real question is, will you have any metal left after polishing  Jk, those BBKs will clean up and are great actions once you do.[/QUOTE]I was wondering about that old ugly BBK action, rumors were that many were not properly heat treated. Olympic said they were made of 4140, so this one at 34 Rockwell C would be at 148,750, entirely adequate for the 450 Ackley build I intend to use it for. [/QUOTE] | |||
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Yes somewhere in the thin casehardened skin, but not in the soft core. A 10 or 15 thousands case isn't going to add much shear strength to a thick lug abutment. | |||
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Chamber pressure -> bolt thrust -> bolt lug shear stress. Lug shear stress level to be kept below specified minimum yield strength. As well as chamber/barrel stress levels. And brass not strained to rupture.  | |||
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I wonder if anyone has a "Set back" 1908 or 1909 that they would section and send to have the lug seats tested? dang, the BBK.. cast and rough! -- Les told me, himself, that he thought a blacksmith could make an action ... opinions vary band of bubbas and STC hunting Club Information on Ammoguide about the416AR, 458AR, 470AR, 500AR What is an AR round? Case Drawings 416-458-470AR and 500AR. 476AR, http://www.weaponsmith.com | |||
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This is like saying that we should use solid steel for broom sticks because it is ten times stronger than wood. (Actually oak is stronger than steel but that is for another discussion) It is less important what the shear strength of Mauser steel/strength is (whatever it is, over the years) because you can't possibly get enough force against the lugs to make anything break. Even with annealed 1020 steel. The brass case will act as a relief valve. Once we get steel cases and screwed in primers like we have in Tank Cannons, then it might be a concern. Chamber pressure is not contained by the receiver; only the piston area that it can act upon; usually about .140 square inch. That is why we use chrome moly barrels and they never fail. I know there are Mauser lovers and Mauser haters. I just go with reality. How many Mausers have you seen with the receiver lug seats sheared through? | |||
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Yes, I have. They are dead soft. I have a rather large presentation on this topic I put together earlier this year. I destroyed several actions to get varying types of readings. Jon Speed provided me with several relevant source documents. Hopefully here at the end of the year I will be able to get that project finished. Currently I am not able to host photo's on AR, but my website is being rebuilt and when they get it done, I am supposed to be able to host again. So either way, I will get it put up on my website, or post it here. A few quick notes: Gunmaker is correct, the original pack specified around the lugs and the bottom tang of the receiver. This is the "old" method, ie, pre WWI. So testing anywhere but there is a useless endeavor. Using Rockwell C scale is not a good scale for testing case hardening unless the case is (from memory) thicker than .040" I'll have to double check that as I don't remember at the moment. To the question what SHOULD they measure. Interwar chart (1934): Receiver - 5-25 150kg (Rockwell C) and 75-85 30kg (Rockwell Superficial 30N) Bolt - 30-50 150kg (Rockwell C) and 80-90 30kg (Rockwell Superficial 30N) Those measurements are taken from the front ring and are for the DurFerrit process. I have examples of Mausers there are too soft and examples of Mausers that are TOO hard. I have a bin full of parts with issues. I save them just for conversations like this. Anytime you make the quantities that Mauser manufacturers made, you will have problem parts make it through QC. Nathaniel Myers Myers Arms LLC nathaniel@myersarms.com www.myersarms.com Follow us on Instagram and YouTube I buy Mauser actions, parts, micrometers, tools, calipers, etc. Specifically looking for pre-WWII Mauser tools. | |||
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Nathaniel how are you doing? When you say you have Mausers that are too hard, what does that mean? Too hard to drill and tap, too hard so that it is brittle and not safe, looking for some clarification please? I'm strictly an amateur and a student, nothing more. | |||
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No but the lug seats fail, yield, are permanently deformed and the safety lug engaged. Effectively scrapping the receiver. | |||
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They "fail" very rarely, in my experience. Early ones. I find Mausers are very reliable. Just avoid pre WW1 ones for anything over 45K psi, or have them re heat treated. No reason to condemn all Mausers. They are what they are. | |||
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Lug setback indicates yield strength exceeded just enough to cause permanent deformation. Load too hot chamber pressure too high. Lugs sheared right off indicates yield strength grossly exceeded. With other components to fail as well. | |||
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I want to hear from anyone who has seen a 98 Mauser with both lug seats sheared through. So far, zero reports, to me. Just do what we have said for decades; use actions made after WW1. With ones made in the late 20s and 30s the best. You won't have any issues. I have never seen a receiver made in those years, set back, and never heard of a receiver sheared through. Lots of theoretical stuff; we already know how to manage Mausers to make sporting rifles on. For those who do not trust Mausers, I recommend using only Remington 700s. | |||
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"Failure" is a relative term. I do not think anyone is claiming that a failure would be so catastrophic as to shear both lugs or lug seats. Is setting back far enough that material flows making the bolt difficult to open and close, a failure? What about cracking through the bolt lug to point of starting separation? Is that a failure? Or when the sidewall of the front ring starts to seperate from stronger and more rigid bottom of the receiver? (there is a reason Mauser moved to a large ring) On the topic of 100% catastrophic failure, in July Mr. Speed sent me the following comment in our conversation of heat treat at Mauser: "one other Cool test report 1948 shows that Bolt Lug Shear strength was 11,800 ATM a new item of data we rarely hear about. Another test from same period Action /bolt pressure tests show over 100,000 PSI without critical fractures! In Bolt lug shear test bolt is placed face down with lugs resting on holder then Industry Press pushes down at end of stripped bolt." Jim, doing well, thank you. When I say too hard, I mean they exceed the specified hardness and have experienced some form of damage, most likely due to that hardness. A good example would be a Mauser 98 bolt that the right lug has nearly separated completely along with pieces of the bolt face broken off. From the interwar specs given previously, this bolt should measure 30-50 Rc. It measures 40-71. Was this the cause of the failure? We have no way of knowing for sure, but it likely contributed. Nathaniel Myers Myers Arms LLC nathaniel@myersarms.com www.myersarms.com Follow us on Instagram and YouTube I buy Mauser actions, parts, micrometers, tools, calipers, etc. Specifically looking for pre-WWII Mauser tools. | |||
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11800 ATM is like 175K psi! | |||
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22 RC is the core hardness in the cold drawn state. 90,000 PSI yield strength. Not case hardened. | |||
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Dunno where you are getting your values from. Estimated Mechanical Property Ranges for "Grade 1030" Tensile strength (psi) 68,000 - 78,000 Yield strength (psi) 38,000 - 48,000 Elongation in 2” (%) 15 - 25 Reduction of area (%) 35 - 45 Brinell Hardness (BHN) 140 - 170 https://www.eatonsteel.com/103...0%20140%20-%20170%20 But a hot forged receiver that has been stress relieved after forging would not have work hardening to increase the yield strength from cold rolling. And a Brinell hardness of 140-170 is far below the minimum Rockwell C scale of 15. | |||
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http://www.interlloy.com.au/ou...ht-carbon-steel-bar/ | |||
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2nd time. Mauser receivers are not cold rolled or work hardened which significantly increases the yield strength. You have chosen the highest yield strength of a small diameter cold rolled rod. That yield strength decrease as rod diameter increases. And if Mauser receivers were 22 Rc at the core they certainly would not be getting below 22Rc at the surface. Which they frequently do. | |||
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IF I'm just one of those rubes that have no problem using quality military contract Mauser 98 actions to build world class rifles worthy of keeping in the family for the next 100 years. More people need to read: Real Men Dont.... A chapter needs to be appended that covers: Real Men are secure enough in their manhood that they can pull the trigger on a custom Mauser built by a talented gunmaker and not get the vapors worrying if their life insurance is up to date. | |||
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Sure a lot of well known custom gun makers who test the locking lugs with a 3 corner file, it it cuts its soft if it sorta bounces off it good to go..The outside skin is hard and the core is soft there fore if the gun gives way to a hoty a Mauser puffs up an may split a bit but not likely to fragment, whereas as a Win. mod 70 being hard with come appart like a hand granade and toss sharpnel in every direction, but the mod 70 takes a damn hot hoty to blow up, I had trouble blowing up and old rusted up mod pre 64 in a tire and loaded to the gills iwth Bullseye it finally gave and totally exploded into peices with a compacted load the barrel looked like a barnes X 577 fully expanded. that gun came out of a stock tank some years ago apparantly..Just my experience and not all that scientific and a little heresay not admissable in court. Ray Atkinson Atkinson Hunting Adventures 10 Ward Lane, Filer, Idaho, 83328 208-731-4120 rayatkinsonhunting@gmail.com | |||
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Just what percentage of those millions of Mausers were recycled into custom Mausers built by talented gunmakers? A teeny, tiny, fraction of a sliver. And you probably aren't building on ones that have signs of failure. I am assuming you would rectify one of your builds that came back with lug setback too. And the other millions and millions Mausers?? | |||
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Why would I?  As with any manufactured item, not every one is perfect. But the HUUUUUGGGEEEE majority are and I don't lose any sleep over it. | |||
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I think the thread is informative. I just don't buy into the irrational hysteria over soft Mausers. 30 years ago back in school at TSJC I built a few rifles of my own. Both on 09 Arg actions. My 30-338 pushes a 180 @ 3150 all day into little tiny groups as well as my equally accurate 25-06. The bolt gets a little sticky at 95 degrees on the 06. Usually antelope season isn't that hot. I never heat treated these actions and have no problems with them. I have sent other 98 actions out for heat treat on occasion. Just not on a regular basis. As it's not normally needed. | |||
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You wouldn't. The point is your level of comfort and confidence is based on a premium action, that you have examined and assembled. Which has very little in common with a run of the mill action, built by whomever of unknown experience. The latter may significantly reduce the margin of safety which is less than modern actions of modern materials and heat treating to begin with. No irrational hysteria here, modern steel and heat treatment is just vastly superior. | |||
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Doug, not sure what your actual beef is with Mausers, if you don’t like them then don’t use them. I just rebarreled a 1917 DWM GEW with an 8x57 L/W pre-fit, screwed in perfectly, shoots like a dream. 200 gr Hornadys over 48 of Varget/ Ar2208 for 2530 fps and according to a few manuals runs at 50k. Absolutely love the thing. | |||
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The run of the mill Mauser is the world's standard bolt action. Not some crap shoot that could blow up in your face. | |||
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Illustrative purposes only (not for design) estimated shear stress on my Zastava LK M70 416 RM bolt lug (ejector side with split):  Load pressure P = 65,000 psi Case head inside dia. d = 0.420 in Bolt thrust F = P * A = 65,000 psi * pi/4 * d^2 = 9000 lb or 4500 lb on each side Approximate split lug dimensions L = 0.4 in, W = 0.2 in Shear stress S = 1/2 F / (L * W) = 56,250 psi Assume AISI 4140 with 30 Rockwell C hardness then tensile yield strength TYS = 135,000 psi Shear yield strength SYS = 0.58 TYS (von Mises yield criterion) = 78,300 psi S/SYS = 56,250/78,300 = only 72% of yield strength | |||
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On a bolt ???? Not likely | |||
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Looks like a lot of you guys might be better off NOT using any make, model or year of Mauser rifle product; they are obviously unsafe and un reliable, being made from low quality materials and poorly heat treated. Best stick to Rem 700s; as I said before. You will sleep better at night too. Others of us, will continue to use them. | |||
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No beef with Mausers, love the design, own a few commercial versions and am making more from scratch. Just not impressed with metallurgy and hit or miss heat treatment of days gone by. Don't think we should be embellishing the strength either. | |||
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