I see you still completely missed my points, Southernfryed. I don't dispute what Fred or ANY othe Savage expert has to say. I welcome their knowledge. And, I am perfectly able to understand the problem, NOW that I worked through it and see where it actually is located.
But none of that specific information came from the net or from Fred or from anyone else. I worked it out myself and posted most of the process while it was going on. Either you didn't read and understand or I didn't present it in an understandable form that you could understand. OR you're still in that "catasrophic/authoritarian" milieu. Re-read my last post, it's mostly all there AND the WHY of the problem. No flame or diss intended, or any of the other "politically correct" BS.
As I see it, the WHOLE enchilada could have been nipped in the bud or stopped in it's tracks IF Fred or one of the other experts would have simply stated the actual problem specifically, i.e., 68KPSI is too high a pressure for the Savage, AND the reason; It causes bolt setback because of the design of the bolt abutments or the lugs are too soft OR, whatever actually was the cause, NOT, just that the Savage just wasn't engineered for the Lapua cartridge. That response didn't satisfy people without knowledge because they kept asking, OR, those, like me, who have a very deep knowledge base and interest, and need a **** of a lot more than "You just can't do it, because". I didn't read any thing like this or was anything like it pointed out to me. Wish it had of been, It would have been very useful to me in many other ways.
If he/them/they had put that in a canned response to all the questions they kept getting, I guarantee after a few read it, it would have been scattered all over the net and EVERYONE with an interest in doing a 338 Lapua on the Savage, for ANY reason, would have gone on to something else, and NO more emails. I would have though about it more, said "Yeah, thats right, whoops, forgot about that", went on to some measurements, and continued on with my normal projects. BUT still, IF
I wanted to do a 338 Lapua based chamber, I would have loaded to the pressure level required for the Savage action. No muss, no fuss, simple as pie.
But that didn't happen and this is the result. It is also the usual result of many other questions of the same kind relating to ANY conversion on many other forums. The usual amount of BS relating to limited knowledge, people not quite understanding or not fully reading or reacting to all the million and one other things we humans get all tweaked over, or just getting whizzed on for no apparent reason. NO flame or diss intented or implied or any of the other "politically incorrect" BS.
Just like jcoop said, most people in this business are just TOO conservative to step outside the boundary's and look at things from a newer perspectiv, let alone speak about it. Many are more mechanically inclined to do the work, but not necessarily machematically inclined to do the number crunching, or are not interested.
The old timers that taught me are long dead and there weren't all that many of them, and there aren't all that many like me left either. There isn't anything wrong with all the new technology, I love it, use it and I stay abreast of the latest innovations, but I think that technology has left out a lot of the "hard earned by sweat equity" things you learn by trial and error. Way to easy to design a new cartridge, have a reamer made, calculate all the parameters and come up with a rifle without getting your nose bloodied now and then. But it is very nice to be able to do it and stay clean.
How do you like your Edge.? What bullets/weights, powder, primer, case brand etc, and pressures do you run? What is the accuracy level and distances you shoot? That cartridge has interested me ever since I first encounted it. I almost did a 338 RUM many years ago when it first came out. Wanted a "REAL" varminter. I played with the 300 gr Sierras in my 338-06 for a while, but circumstances prevented me from getting anywhere else. Now the 50 cal has my attention, forget that puny 338 RUM "toy".
You don't have any worries mate, as long as you don't get the pressure over 64KPSI MAP, which is SAAMI correct for a RUM based cartridge.
I also looked at the RUM case for doing several different large bores but had to settle for the Rigby/Lapua case to do a .510. The only other case close was the Jeffrey. 0.620" rim OD and it is just TOO big for the Savage although it could have worked by keeping the pressures down below 45KPSI, just as keeping the pressures down below 45 KPSI for the Rigby case works. The bolthead wouldhave lost it's steel rim completely.
One thing you can do for me is measure the OD of the large shanked receiver AND the bolt lugs, length, width and depth AND measure the thickness of the receiver segment where the bolt just entes the receiver chamber end. Those numbers would give all the information required to figure out the actual thickness of the segment. A picture of the large shank receiver ID looking into the end would be worth a thousand words along with the actual measurement . I could ratio the picture and extract a lot of information.
I don't have any specific numbers to go by and that would go a long way in understanding also. I don't think the bolt lugs/boltheads are any different that the small shank parts, at least from looking at available parts lists, there is NO designation as to large shank or small shank parts that I see in Midway or Brownells.
My numbers are - Large shanked barrel 1.12" OD, Small shanked barrel 1.055" OD - difference is 0.065". That would make the ID of the receiver the same as the OD 1.12"-DUH-do ya think Mac?
and basically add the same amount to the depth of the bolt lug abutement which is 0.154" now, to say 0.220" thick.
Also I don't know exactly if the design of that section of the chamber end has been changed. You would have to do those measurements and comparisons yourself.
I boils down to a shear modulus calculation rather than just a simple shear yield strength calculation if all the other measurements are the same. You basically gained 0.065" x width x lenght, which would change the stress modulus numbers. By how much, I don't know. I didn't do a circle segment calculation either for that matter and that is what the "cresent" I was refering to, is. But eyeballing the segment, it looks to be slightly over 1/4 of the OD, roughly 100°. C=Dx Pi so that would be roughly 1.35" x Pi = 4.24x.30 = 1.27"w x .400d x .220h = .112 cu in roughly. Using 0.154h = 0.078 cu in. .034 cu in difference. Doesn't sound like a lot does it?
But we are actually talking about "only" 4KPSI differential also, and a stress modulus section of roughly 1.27" x .400"x .034" additional support area.
Stress modulus is measure in Giga pascals, for steel that is 79 GPa or 11,148,000 psi and is defined as G=FI/delta-x X A, force times height divided by Delta x times Area
I have no way of empirically measuring tan theta without destructive testing, and about now I start getting headaches anyway.
The force would be the pressure over the bolthead, roughly 18.7KPSI for 68KPSI for a Lapua case, times the height divided by deflection delta-X times area.
The shear modulus is defined as the ratio of the shear stress divided by the shear strain. One psi is equal to about 6900 Pascals and a Gigapascal is equal to a billion times a Pascal, just add 9 more zeros after the last zero in 6900, 6 900 000 000 000 Pa. A GPa is equal to about 145,000 psi. Gets a little thick doesn't it. The deflection would be very small but because of the large numbers, but you need a piece of software to crunch the numbers, I don't have that software.
Besides, I lost most of you way, WAY back, and I'm not an engineer, just an interested party. If I had the money, the equipment, etc I would present the data to you for informational purposes ONLY.
The simple answer is that small amount is enough to offset the pressure differential.
It also boil down to the 4KPSI difference in pressure between a 300 WM and the 338 Lapua, and the difference in bolt head area presented to the bolthead and transfered to the lugs. That small amount, 0.0650" thicker, is all that was required to adjust for the pressure differential. That pressure differential is not a lot but just enough to cause the redazz in this case.
And I don't know for sure if the lug setback occurred on the lugs, on only one lug and maybe the lower abutment or on both the lug abutments.
It would really be nice, and it wouldn't bother me in the least, if someone with specific, actual empirical knowledge of WHERE it happen would come forward and just say "All you pontifications are sh**, HERE is what/where it happened...!!! THAT would settle the whole argument and point the way to a solution. Just as long as I KNOW for a fact it was someone who DID IT, and not some SFB trying to be funny. That still doesnt negate how I went about working through the problem without actually doing a destructive test on a receiver.
If you think of this whole thing simply as a tube within a tube within a tube, with one closed end, nothing esoteric, just a simple physics problem, the pressure occuring in mili-seconds, and one part being nothing more than a part in a hydraulic system or in this case a gas pressure system. Looking at it THAT way makes it a lot more understandable. That's what my old long dead math professors tried to pound in my brain. Reduce all the factors to simple physics problems and then solve.
My presentationis also simplistic and to get close to the actual numbers an engineering stress analysis would need to be run. I would do it if I had the bucks. Anyone really interested in this problem academically could probably pay Varmint Al to do it, he is an engineer and has the tools and software to do it.
Baring that happening, ALL the rest of the BS is just that, BS without a solution. All smoke and mirrors, and whisky talk around the camfire.
Luck on your quests.