Heat treating will likely be an absolute requirement after machining, regardless which materials are used. Without heat treating afterward for optimal strength (however measured), it is unlikely I would ever want to shoot any action, regardless how carefully and accurately machined, unless it was restricted to chamber pressures well below 25,000 lbs. psi.

Major improvements in action making in this day and age lie to a substantial extent with the improvement in heat-treating knowledge and equipment. Materials have improved somewhat, but I suspect knowledge of temperatures and treatment duration to use, methods of heating, reading of temperatures, varied treating in different locations on the same piece of work, and control of cooling rates have contributed at least as much as new materials to the quality and safety of modern rifle actions.

AC

You can put all the pressure you want in a dead soft steel action with brass cases, if the steel is thick enough. The heat treat is for weight reduction, wear, and resisting rust.


That knowledge was around in a day and age many generations ago.

Good point Alberta.

Clark, right you are about size, however the inquiry was about manufacturing a Mauser action, and absolutely no Mauser sized action would be suitable for use without the application of the proper heat treatment and metallurgy, unless, perhaps, the bolt lugs lock into the barrel itself.

In fact, I dont think that anyone would want to lug around any firearm of the size that would be required in order to not have to consider heat treatment as important, for sporting purpose anyway, with the exception, perhaps, of firearms where the bolt lugs lock into the barrel itself and even then the bolt should be heat treated. However, excepted, also, would be low pressure cartridges including black powder.

By the way, what firearm(s) do you know of that you can put all the pressure that you want into that is made of this dead, soft steel, and what were its original chamberings? Just curious.

Theo

i am surprised at how many people think a mauser action is the neatest thing since sliced bread. how many 1000 yard rcords are currently held by a mauser? how many bench rest records are held by a mauser? (i'll give you three guesses and the first don't count) 0 is the correct answer

Mr. poulsbo, perhaps you believe the only thing guns are good for is 1000yard matches, others however have many other reason to think a Mauser is their favorite action... and the reasons given would be right for them. Enjoy.

Last year one of the forum members, in the orient as I remember, made an action from 4340 steel.He very successfully used the rifle in competition.

Poulsbo,
I've never shot anything at 1000 yards and I don't know much about benchrest shooting but for hunting big game I want a rifle that will function without fail in all conditions. For that I'll take a Mauser (or Model 70).

Jeff

I guarantee you that a properly reworked Mauser 98 action with a quality custom barrel that's been properly chambered and then correctly bedded to the stock is capable of five-shot groups of under and inch at 100 yds., which is plenty good enough for any big game hunting anywhere in the world.

No, no one is using Mauser actions on benchrest rifles or varmint rifles these days, but who cares? Are we hunting statistics or big game animals? I think a lot of guys are too preoccupied with the icon of "benchrest accuracy" these days, and evidently have varmint hunting requirements confused with big game hunting requirements.

In hunting country, Mauser-type features count for a whole lot more that benchrest features.........

AD

Theopolis,
Do you understand the problem with the 25kpsi cartridge loading limit not respecting what caliber and what size Mauser?
Are you into gun math?
I am, but I don't want to bore you to death.
Can you calculate which Mausers with which calibers can go until the brass flows without reaching the yield point for dead soft steel?
my stress analysys on a handi rifle

allen day,
I am making MY varmint rifles with Mauser actions.
And I am somebody

I'd make a varmint rifle on a Mauser action myself and feel darned good about it!

My next project, which comes close to this concept, is a .22-250 based on a Model 70 short action with a Hart barrel. I'm not a bit worried about accuracy. After all, if the M70 has been good enough for the years to win numerous high-power championships as well as the 1000 yd. Wimbleton, it's good enough for any or my requirements. Of course, the benchrest guys tend to forget about that track record.......

AD

Post deleted by Chuck Nelson

After 40 yrs. and about 100 rifles, several of which were used for self-defense and crew protection in remote Grizzly country, I would not own a rifle that was NOT of Mauser functional type. The ONLY exceptions to this are certain lever actions for specialized purposes.

Many of my unaltered Mauser and Pre-64 rifles will and do shoot Nosler PT. bullets in warmish loads into sub-moa groups out to 300 yds.; I do not see what more one could ask for or need, in terms of hunting.

I know quite a few ardent benchresters and none of them use those specialized actions or anything resembling them for actual hunting.

Infosponge,

Thank you very much for the link. It was highly informative about you! I only stated that I had not heard the term 'modulus of toughness'.

Obviously, you like almost every other poster on this thread, believe that will a little Google searching you qualify as a Mechanical Engineer capable of design and specing out a rifle action. Got news for you, you aren't even close.

Issue number one. I would NEVER NEVER want a tough rifle action. Toughness is the area under the 'stress versus strain' curve which exists between the 0.2% elongation yield point and ultimate failure. In other words it the area under the curve of the plastic region (non-linear) of the stress versus strain curve.

What I want is a rifle action which is resilient! The 'modulus of resilience' as your MIT post calls it, is the area under the elastic (linear) portion of the stress versus strain curve. This is the place you want your rifle to live in.

Lars45, I have far more Mechanical Engineering credits to my name than you, although I bet you have me beat on the Electrical engineering side. The concept you are struggling to communicate to the 'team' is: ENDURANCE LIMIT. Theoretically the endurance limit of steel exists at 50% of the steel's ultimate strength. Also, theoretically, if you load the steel at or below it's endurance limit, the steel's fatgiue life is infinite.

This is all well and good, granted that you know what the ultimate strength of YOUR individual peice of steel is (steel is spec'd at a minimum ultimate) and YOU KNOW how to calculate the von Mises stresses acting upon the peice of steel in question.

von Mises stress - there class Google away and figure out what that term means. Getting the definition is the easy part. Figuring out how to calculate them can get tricky.

Blue,

If all you want to do is scale up a Mauser M98 so you can chamber BIG rounds that is great.

Make sure you scale every aspect of the action i.e. length, width, radii at corners, etc. If using a through hardened steel acheive a through hardness of Rc 30 -35. Stay away from through hardened steels higher in hardness or lower. If you are using a case hardened steel achieve a case hardness of Rc 55 -60, with an effective case depth of 0.02" to 0.035" deep, and a core hardness of Rc 30 - 35. Appropriate through hardened and drawn back steel alloys would be SAE 4340, SAE 1340, SAE 4140. Appropriate case carburized steel alloys would be SAE 8620, SAE 4320, SAE 9310, DIN 18 CrNiMo7-6. As I said scale up the Mauser action in every regard the same. It must be a true 3 dimensional scaling up, or you will be in for trouble. Also, be very mindful of filet radii. Maintain as close as possible a tolerance between the ID of the action's lug through bore and the diameter of bolt (you want to minimize this clearance as much as physically possible). As you increase the hardness of the steel, fatigue strength life drops exponentially. So keep to the hardness values I recommended. This advise should suffice to keep you in one peice. Of course, this assumes that the Mauser action you are scaling up is properly designed in the first place!!

Good luck with your quest.

Scott

Clark -



Let me ask you a couple of questions...



Do you understand why Mauser, Springfield, and other actions of similar ilk were/are heat-treated by their manufacturers?



Would you explain why you think that decision was/is unimportant?



Thanks,



AC

With regards to issues surrounding old Mauser surplus actions re-worked for modern sporting uses:

Lug setback? I've heard of this happening in surplus Mausers, is it a concern? One 'smith stated to avoid em if one planned on loading ammo above moderate pressures. (did not ask what moderate pressures were!)

Heat treat issues: I've also heard alot of the Mausers having poor heat treating especially if built during war times when quality control could/was iffy. Darcy Echols addressed this concern awhile back in response to Jack Belk's comments on heat treating old Mausers. IIRC, Darcy was not a fan...........

MtnHtr

Well, getting back to my original question, it appears that one could start out with a 2 inch round piece of bar stock, drill centers, put it in a lathe, and make the first cut by boring a hole straight through the piece of steel. then, bore one end a bit bigger for a certain length, and thread that hole. Where it looks like it may get tricky is in two places, namely the flat sides (more properly called the lug raceways I believe) and the lug recesses. How do those two areas get machined? What tool would be used for those two spots?

Blue

Blue,
Metal shapers used to be popular before WW2.
I have one, but it gathers dust sitting next to a vertical mill, the story is the same all over the world.


canuck,

Quote:

---

Do you understand why Mauser, Springfield, and other actions of similar ilk were/are heat-treated by their manufacturers?

---

As I said,

Quote:

---

The heat treat is for weight reduction, wear, and resisting rust.

---

Heat treat does not change the modulus of elasticity, just the yield. Brass has a yield below annealed steel, so if the steel is thick, the brass will flow before the steel will.

--
A society that teaches evolution as fact will breed a generation of atheists that will destroy the society. It is Darwinian.

Clark is right here, you guys are just not seeing his point.

Let take the thinwalled pressure vessel equation:

stress = pr/t or Pmax= yield stress*thickness/radius. So if you use a steel that has a yield stress 1/2 as much as 4140, then use twice as much of it to get the same strength. Or for locking lugs, then use more surface area for a weaker steel.

Mausers original design was to have a ductile core with greater surface hardness. So it would not blowup if subjected to higher pressures, but the hard surface would help with wear resistance.



Also the part about a guy in the orient that built his own action never did post pics of his gun when asked to.



On Mauser Accuracy, I have 2 M98's in 06, they both shoot sub 1" with 165 corelockts. I also have a Turk 8mm self sporterized with a heavily worn barrel($125 total includeing scope). It wouldn't shoot 150 speers, but I changed to 170's and it now shoots in the .8" range. It's not a work of art, but it works.

Blue,
You can pull the ways on a lathe bed using a broach or if your friend has an edm you can burn them. The ways in an action are essentially the same as a cut-rifled bore. The lug ways are cut the same way.

In short you can do it with a mill and a lathe. For that matter you can do it with a lathe and post grinder alone. You can make a round Mauser type action with all the internal features but without the flat bottom and save a bunch of time as well as having a round action that the bench rest folks consider necessary for maximum accuracy. Of course then there's the Mausers slow lock time. But as someone said earlier: who cares I'm hunting.

The originals were made before the days of CNC and wire EDM's with lesser machines than our modern mills and lathes so have at it and enjoy.

I understand Clark's point perfectly.



The problem is, tensile strength of the material (technically, "absolute strength") is not the only consideration directly relevant to making an action which will function for more than one shot.



Tensile strength refers to the static force needed to permanently plastically stretch the item being used to the point of catastophic failure with a single application of load.



First off, there are a number of different types of stress/strain applied in the functioning of a rifle action.



1. One of the principle considerations is Shock Stress. According to Machinerey's Handbook, "A suddenly applied load will produce the same deflection, and, therefore, the same stress as a static load twice as great..." Additionally, the amount of stress will be further increased by any travel of the piston (the cartridge case).



2. Fatigue Properties come into play. When a material is subjected to many cycles of stress reversal or fluctuation of pressure, or variation in magnitude without reversal, failure may occur, even though the maximum sress of any one cyle is considerably less than the value at which failure would occur if the stress were constant. In the instance of a rifle action, firing numerous cartridges is somewhat analagous to operating a small gas-powered trip hammer to strike the bolt, the locking lugs of which in turn strike the receiver.



3. The stresses involved in firing a cartridge are not "Simple Stresses" because of the number of action parts (two or more) involved in opposing the applied pressures, and the relation/fit of those parts to each other and the piston. They are "Combined Stresses". An action may be loaded (and is, to some extent) by combined stresses in such a way that the combination of stresses may act with a cumulative force at a single point.



4. To the extent the stresses produced by the firing of a cartridge are not applied with perfect symetry, the bolt becomes an eccentrically loaded column, with a "bending moment" and greater "strength" is required to resist those stresses.



5. It is common to build into machines made of steel a minimum working safety factor of 20%. That is, a machine intended to take 60,000 p.s.i. of "Simple Stress" is designed for a minimum strength of 72,000 p.s.i., and so on.



6. Hardness is important because according to Machinery's Handbook (page 473) "Steels that have been fully hardened to the same hardness when quenched will have about the same tensile and yield strengths, regardless of composition and alloying elements."



The Society of Atomotive Engineers has prepared a chart showing the relationship between hardness and tensile strengths of steels. It can be found on page 474 of Machinery's Handbook. It shows steel with a Brinell hardness of 100 as having a yield point of about 60,000 p.s.i. To get a yield point of 80,000 p.s.i. takes a Brinell Hardness of about 150.



SO...



Let's see, if we have a shock load of 25,000 p.s.i, that could apply about the same stress as a static load of about 50,000 p.s.i. That load's affects will also be increased by any bending motion possible if the bolt is not perfectly supported by the locking lugs and receiver ring. The affects will be further increased by the fact that he load is applied many times, not just once. Depending on design, tolerances, and "trueness" of surfaces to each other, the stress may further be cumulative and applied at one particular point (cracked locking lugs, anyone?). Then, on top of all that, we should have a safety factor of 20%.



Though it is possible to machine steel with a Brinell hardness of 150, it sure ain't easy, so we commonly use steel which has a much softer index rating than that. Then manufacturers presumably harden it to give it the yield strength and wear resistance needed.



These considerations are why I think rifle actions should be heat treated for additional hardness & strength, regardless of the steel from which they are made. Personally, I want no truck with actions which are not heat-treated, and which are firing cartridges with working pressures of more than about 25,000 p.s.i. They may work fine the first shot, the first 100 shots, or the first 1,000. On the other hand, I am not immortal and don't want to to take too many unrequired risks. Fast driving of my fast cars is enough of that.



You, of course, may shoot whatever turns your crank.



AC

What you seem not to understand, though, is that hardness and strength (ultimate/tensile strength) are not the whole story when it comes to metallurgical action safety. In fact, by themselves, hardness and strength miss one of the most important plot lines: toughness. The difference between the elastic limit of the material and its ultimate tensile strength is largely responsible for the toughness of the material; and it is this toughness, at least as much as hardness or ultimate strength, that any heat treatment should seek to optimize (as long as adequate, though not likely the highest possible, hardness and strength are maintained).

Toughness represents the ability of the material to absorb energy without fracturing. It is the opposite of brittleness. Old, case hardened actions, with their low tech steels and ductile cores, can deform far more, and absorb far more energy than most modern steels if those steels are through hardened to very high hardness. When made very hard, the difference between the elastic limit and the ultimate strength limit of the material is comparatively small. Instead of deforming and absorbing more energy when overstressed, the very hard, very strong, but very brittle steel fractures -- and fractured steel/action disassembly/"my gun blowed up!" is the last thing you want when an action is overloaded! Much better to have the lugs set back or the action bulge than to have the gun blow up in your face.

InfoSponge; What are the dimensions of "toughness"?. Or is it just an adjective ?.
Thank You!

It's more than just an adjective; it's a very real and measurable physical property of the material or test part. Toughness is usually dealt with as the modulus of toughness, which is defined as the work done on a unit volume of material as a simple tensile force is gradually increased from zero to the value causing rupture. Modulus of toughness may be calculated and/or measured as the total area under the stress-strain curve from the origin up until the part ruptures. Units for the modulus of toughness depend on what system of measurement one is using, but MPa is common.

All I can say is WOW !!!

This thread is VERY VERY SCARY!!! No one who has posted on this thread seems to understand the mechanical engineering principles at work sufficiently to safely design a rifle's action!

All I can say is DANGER DANGER WILL ROBINSON!

Modulus of toughness??? Never heard of that one before! The definition you provided is typically referred to simply as TOUGHNESS!

I could begin to explain the real information one would need to design an action, but I am too lazy to start what would ultimately become a 300+ page report. Besides that some bonehead would get it wrong, because this isn't simple easy stuff believe it or not, and kill themselves. I am serious children, the math and concepts involved are indepth and not simple, there is a REAL reason that Engineering Schools suffer the highest drop-out rates!!

Scott

Russ,

I concur. With the proper set-up one could easily replicate at least 95% of a Mauser M98 with nothing more than a lathe, a vertical mill, and a rotary head.

I personally would love to have Clark's shaper! Although, cutting the raceways with a shaper would be tedious! A broach bar is much quicker and more accurate!

Scott

Scott

Nobody, at least not me, said anything about designing an action. All I want to do is have my very talented machinist friend duplicate some mauser actions for me in the sizes that I want. I plan on using the same steel that everyone else uses, and I also plan on having it heat treated by somebody that knows what they are doing. And I certainly don't plan on selling them to anyone. I just wanted to know if anyone else had tried it, and if so, how they did.

Blue

Fool.

MIT OpenCourseWare a good enough engineering reference for you?

http://ocw.mit.edu/NR/rdonlyres/Materials-Science-and-Engineering/3-11Mechanics-of-MaterialsFall1999/1B957032-BE5D-4475-8CDE-6D29E9EB6502/0/ss.pdf

Quote:

---

The area up to the yield point is termed the modulus of resilience, and the total area up to fracture is termed the modulus of toughness; these are shown in Fig. 13. The term modulus is used because the units of strain energy per unit volume are N-m/m3 or N/m2, which are the same as stress or modulus of elasticity.

---

I like the part in the stress strain relationship where necking begins



I think I can see why guns are like switching power suplies, designed by an individual. If the above posts were a committee designing a gun, we would have all the elements of the Clinton cabinet, as described by Robert Reich, minus the decorum.



--

A society that teaches evolution as fact will breed a generation of atheists that will destroy the society. It is Darwinian.

Scott, have you ever done anything or built anything? Do you own any guns? If so you can continue in this conversation. If not, then.............

From what I gather 4140 is a common Steel to be used for makeing guns. You can also get it leaded 41L40 wich has nearly the same strength properties, but is easier to machine. The only hazzard is don't weld on it without good ventilation.

From what I have read the stress number of cylcles limit for most steels is approximately 1/2 the yield stress. So if you design around the 1/2 yield stress then you should theorectically have infinite cylcles without failure.

Senior in Engineering, 2 semesters to go in EE with CS minor. I do take some Mechanical classes just for the fun of it though and do run my gun design questions past my Mechanical professors who are also gun nuts and like to shoot.

"6. Hardness is important because according to Machinery's Handbook (page 473) "Steels that have been fully hardened to the same hardness when quenched will have about the same tensile and yield strengths, regardless of composition and alloying elements."

Alberta, do you have the Author of the book? I'd like to see if we have it in the library.

Infosponge -



I understand very well that hardness and tensile strength are not the whole story . . . As a matter of fact, I thought that was MY point.



One of the earlier contributors to this thread referred to the tensile strength. I was trying to show that even if all one considered was tensile strength, it is not as simple as just comparing the theoretical load of the pressure times the cartridge head area relative to the tensile strength of the material.



Toughness is very important, granted. What I was trying to point out was that it is not as simple as simply looking up the "absolute" or "tensile" strength of a steel and then deciding on that basis whether it is suitable for making an action.



I was also trying to make the point that one should not make an action, in my opinion, without heat treating it for optimal qualities relative to its task.



I was hoping by so doing that amateurs would be discouraged from simply cranking out a copy of an action on a tracer, then touching off high pressure loads in it. In this instance, it might look like a duck alright, but without proper heat treating (which probably will differ at different points in the action), it probably won't fly like a duck. To continue the analogy, it may get airborn but sustained flight is a whole other matter.



LAR45 -



Machinery's Handbook, 26th Edition; Oberg, Jones, Horton, & Ryefell; Industrial Press Inc.; 2000; New York; 2,630 pages; is the current issue of the standard reference "bible" for machinists.



AC

I was also trying to make the point that one should not make an action, in my opinion, without heat treating it for optimal qualities relative to its task.

That really depends on the steel that you start with. Some very fine (and expensive) custom actions are now being machined from pre-heat treat 4140 and pre-heat treat 4340. These don't require post-machining heat treat of any kind, much less a complex case hardening heat treat that varies for different parts of the action. Several modern steels are very adequate for use in rifle actions with comparatively simple through hardening heat treatments (either pre- or post-machining), so complex case hardening heat treatments like Mausers, Springfields, and M70s used to see are no longer required -- unless you really want to acheive (for purposes other than basic function or safety) the high surface hardnesses of some of these older actions.

While we are at it, I might as well add that "toughness" is not the whole story either.



About 50 years ago, when I was a young sprout, I had two actions rebarreled . One was a "long lever" Martini Henry, which was rebarreled to .219 Improved Zipper by an outfit in Pennsylvania. The other was a fully engraved Model 1888 Commission Rifle by Haenel which was rebarrelled to 8mm/06 by the Micro-Sight Company of Belmont, California.



After less than 400 rounds, the case heads of the .219 Zipper ammo had pounded a recess into the face of the action to about half the depth of the cartridge rim. This, of course, substantially increased headspace, and made the action very difficult (sometimes almost impossible) to open after firing. The action was tough enough that nothing split, fractured, or leaked to that point. However, it was obvious that the action was not hard enough to take the pounding it was receiving. None of the loads, BTW, exceeded middle of the range standard load information of the day.



The Haenel, which on reflection had apparently been softened to be fully engraved, and not rehardened, didn't last 50 rounds. The action so stretched that the trigger/cocking piece relation changed after nearly every shot to the point the rifle would fire on closing of the bolt. Again, the steel was tough enough that nothing catastrophically failed, but the gun was still useless after a few shots.



When building a rifle action, the metal has to be metalurgically correct in all respects for the job. At least, that's what my experience appears to tell me.



AC

I don't care how simple or complex the heat treatment is. That wasn't even the topic.

And, as I said, anyone is welcome to shoot whatever they want. It is their cost/benefit analysis at play. I don't personally care to shoot actions which basically copy a standard Mauser with no heat treatment at all.

YMMV

AC

Regarding the initial question: it is not that hard to machine an action. As an ME who has also spent years programming for CNC machines, I have seen many parts that required much more complex operations than rifle actions. Recall that these (mauser-type) actions were being made many years before CNC machines were invented. If they could be made by the millions on simple - although specialized - tooling and machinery, there is no reason that you cannot bust out the CMM, get your dimensions, and then machine a few with some basic reverse engineering.

The being said, there is more to this process than just turning out a piece of steel in the same shape as the original action. These actions were able to be made to their dimensions as material properties allowed. There is a lot of stress on that little piece of steel! Material properties will determine how thick or thin any pressure vessel can be. Look at high pressure steam lines. These pipes hold in 1000 psi of 1000 deg steam day in and day out, but they are not specially heat treated. They just use 4" thick walls!

Now, you could make a receiver without using heat treated steel, but it would not be the same dimensions as the mauser you are holding now. You could take a 3" or 4" diameter piece of steel and bore your bolt ways in the middle of it (a much bigger bolt, BTW), and it would hold lots of pressure without heat treatment - but it sure would suck to carry around all day. Much better to take advantage of improved material properties made available by heat treatments. This way, you can make the receiver as light and yet as strong as possible. That's why heat treament is so important for small arms parts. Heat treatment allows you to use less of a stronger material to do the same job as much more of a weaker material. The result is a smaller, lighter, handier weapon.

Safety of the action is a function of the design and the material properties. You cannot substitute a different material without completely recalculating the design parameters. I could make a very lovely action out of modeling clay painted black, but it sure wouldn't be the same as an original mauser! Material properties of rifle steel are very dependent on heat treatment. As long as you get the action properly heat treated by someone who knows GUN heat treats, your replicated mauser action should be perfectly safe. Maybe even safer than the original with any number of unknown heat treat processes and/or failures. just my $.06 maxman

There are many modern steels that can be used to make a rifle reciever without heattreating. I have used many of them in manufacturing oilfield downhole drilling tools. Steels such as Astralloy, EN30B and now 4330 V Mod (added vanadium) are very strong,with ultimate tensiles up around 175,000PSI(going on memory here so I could be off a bit). Hardness is in the 34-38Rc range.I wouldn't hesitate to build a reciever out of one of these steels and I sure wouldn't waste time and money heattreating after machining.Heattreating the lug area of the bolt head to around 44-48Rc would be a good idea just to make it more wear resistant and prevent galling of the lugs.I plan to do this someday.

Rembo, how machineable are they? Would you need carbide cutters for everything?

REmbo

that is amazing, as I have had many older mauser actions tested by a professional heat treater and have been told that their hardness has been approximately 20 on the Rockwell C scale. In fact, I have had a couple of actions made in South America that did not register on the C scale and therefore had to be registered on the B scale. And now you are saying that there are steels available that would machine out in the 40s on the C scale without heat treating.

The only thing I wonder about that (or I am sure my machinist friend will wonder about) is tool wear when machining something like that. Wouldn't tool wear be significant when machining hard steels like that.

the action that I have in mind to duplicate is the G/33.40 and its close cousin the VZ-33. Both are nice lightweight actions that are just perfect for the 7 x 57 class of cartridges. However, these actions are getting as scarce as hens teeth, and as such their prices are starting to get up there in the $750 range if one buys a whole rifle to get the action. the way I see it, once the programming is done, one could probably make that action for quite a bit less than $750 depending on material costs and tooling costs for each action.

Moreover, I don't even see the need to make the bolts. There are so many surplus bolts around that all one would need to make would be the action.

As for heat treating, I am sure that there are many firms that are familiar with heat treating gun parts, or at least familiar with heat treating certain steels to certain hardnesses. I know Mr. William is working on making a model 70 type action. I am sure he has a heat treater in mind for that action, and I am also sure he probably has a steel in mind.

I agree with you about the complexity of parts that can be made. My friend has HASS equipment, and I cannot believe the complexity of some of the stuff he makes. Surely a mauser action shouldn't be too hard when compared to some of those other parts he makes.

Blue

The way I look at it, the two front lugs on a Mauser bolt a .43 x.373" = .32 sq. in

The bolt trust must come from a case with .470" outside diameter with at least a .030" case wall so inside diameter is less than .41"

That is a inside area of pi [.41] [.41]/4 = .132 sq. in.

The bolt lug sheer stress is then .132/.32 = 41% of the chamber pressure with no brass to chamber friction.

If we use 4140 dead soft with a yield strength of 50 ksi, and shear to tensile ratio of 90%, then we have:





Chamber pressure to deform front two dead soft Mauser bolt lugs, not counting chamber friction or the safety lug in the rear = 50 kpsi 90% /41% = 110,000 psi chamber pressure.



If we use 5160 steel, then dead soft we would be good for 228,000 psi chamber pressure.





There are more things to check, but you get the idea about my above comment about 25 kpsi chamber pressure.



--

A society that teaches evolution as fact will breed a generation of atheists that will destroy the society. It is Darwinian.

Obviously, you like almost every other poster on this thread, believe that will a little Google searching you qualify as a Mechanical Engineer capable of design and specing out a rifle action. Got news for you, you aren't even close.



You are telling us far more about yourself than my post told about me, Scott. I never asserted anything like your purported claim that with a little googling I qualify as an ME or that I am capable of designing rifle actions.



Issue number one. I would NEVER NEVER want a tough rifle action. Toughness is the area under the 'stress versus strain' curve which exists between the 0.2% elongation yield point and ultimate failure. In other words it the area under the curve of the plastic region (non-linear) of the stress versus strain curve.



That is incorrect. The modulus of toughness is the area under the curve from the origin out to the point of failure. In other words, it covers both the elastic (linear) and plastic (non-linear) regions.



What I want is a rifle action which is resilient! The 'modulus of resilience' as your MIT post calls it, is the area under the elastic (linear) portion of the stress versus strain curve. This is the place you want your rifle to live in.



Resilience and toughness are not mutually exclusive, of course. Also of course, you want your rifle to only operate within the elastic portion of the stress-strain curve under normal conditions. An action that is operated beyond the elastic limit and that permanently deforms as a result is not very useful, as has already been well covered in this thread.



However, what happens in atypical and potentially dangerous situations where the action is stressed beyond the elastic limit is a very important safety consideration. If the action is brittle, then there simply isn't much area under the curve to the right of the elastic limit, and the action is not capable of absorbing much energy without failing catastrophically. If the action is tough, then it will undergo a considerable amount of plastic deformation after the elastic limit is reached, there is a large area under the curve to the right of that elastic limit, and the action can absorb a lot of energy before flying into pieces -- hopefully more energy than the cartridge is capable of delivering to the action.



Toughness isn't important under the normal operating conditions of a rifle action, but it is still very important to the design of a safe action. If you NEVER, NEVER want to shoot a tough rifle action, then I NEVER, NEVER want to be anywhere near you while you are shooting your brittle actioned rifles.