I have a commercial Mauser, in single shot configuration.

I am wondering if this would handle a 338 LM? Single feed. So just lay the round in the loading port and close.

Would one need to remove to much material from the bolt/bolthead? And would it handle the pressure?

Some have built .416 Rigbys on standard length Mauser actions so no reason the .338 Lapua wouldn't fit, but it is neither ideal or IMO smart to do so. Same with Remington 700: some have been built, even in the Remington custom shop, but the 700 is not an ideal platform for that size case head.

Some will say no; I would do it on a single shot Mauser; not on a surplus one; you are dealing with a lot of head area with the Lapua. Yes, they build them on standard 700s, but you note that Savage and Armalite developed special larger actions for the Lapua.
I now see that John has already said they are not ideal. True.
Better choice is a 338 RUM.

Comparing the "approximate" bolt thrust of the 338 Lapua to that of the standard 30-06 you can see that there is just a bit of difference. In truth, the 338 Lapua actually operates at nearly the same, and in some cases greater bolt thrust levels than the proof loads used for standard cartridges. The manufacturers won't release proof loads to the public as they deem them to be dangerous. You can see why some manufacturers washed their hands of it until they could build a more massive action.

Govern yourself accordingly.

338 lapua by Rod Henrickson, on Flickr

Heck that is only 58% more.

quote:

Originally posted by ramrod340:
Heck that is only 58% more.

If it was 80% more the bolt and receiver would be nicely stuck together.

If it was 100% more the action would likely be in pieces.

Ah yes. The natural progression of insanity !

I recall reading about an experiment, years ago, where a fellow tested actual transferred back thrust using a 416 Rigby case. The details are foggy. If I recall correctly, he found a pressure range where little actual bolt thrust was transferred, as the case expanded and adhered to the chamber wall. Even leaving a little sizing lube on the didn't effect things in that pressure range. A highly polished chamber changed things, if I recall correctly. The exerimenter said that these results had a lot to do with how straight walled the Rigby case is, and that the more steeply angled a given case is, the more easily bolt thrust is transferred to the bolt face, lugs, and recesses. The 348 Win was given as an example of a case with a notoriously high percentage of actual bolt thrust transference. I might be smokin' some wack, but model 71's seem to kick a little more out of proportion to what I'd expect. However, having firied several different stock configurations on the 86 frame, they all seem to be kickers, regardless. I'm pretty sure 61k psi is out of that sweet spot range found in the experiment. Anyone else read that article? I would love to read it again. Seems like it might have been in an old issue of Precision Shooting.

quote:

as the case expanded and adhered to the chamber

Isn't that part of Ackley and Gibbs' claims??

Could be. I do recall Ackley writing the 348 kicked more due to sloped case.

The reduced taper is mentioned to reduce thrust in the Gibbs article.



Still thinking about if I heard it from Ackely

I stole this but one of several Dozen articles that reference reduced Thrust because of the Ackley design.

By J. Marshall Stanton on 2002-06-04
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Before the proliferation of factory belted magnum cartridges, a devout and steady following of the Ackley Improved cartridges persisted during the 1950’s and into the early to mid 1960’s. Parker O. Ackley, while certainly not the first of cartridge wildcatters to “improve” a standard cartridge, brought a standardization of these modifications to the firearms industry.
Typically, the Ackley Improved concept involves straightening out the cartridge to minimum body taper, and putting a sharp shoulder on the case while leaving the neck at standard length. The increase in powder capacity varies from one cartridge to another, but can be from 3% to as high as 9% depending upon the factory cartridge being “improved”. Part of the genius behind these modified cartridges is the ability to shoot standard dimension factory rounds in the firearm, as well as the “improved” version. Too, simply firing loaded rounds of the parent case in the improved chamber easily forms brass without the need of specialized case forming dies.

In addition to the obvious advantages of increased case capacity, and thus the propensity for increased velocity potential, are other benefits not immediately apparent. One of these attributes is a significant reduction in rearward thrust against the bolt or breech-block of the rifle. This reduces strain on the firearm by means of the minimum body taper of the chamber and case, thus reducing to some extent the amount of rearward thrust, since the case more tightly grips the relatively straight chamber.

The second of these benefits is the fact that typical brass stretch of a fired case is significantly reduced as a direct result of the minimum body taper. This reduction in brass stretching not only minimizes required case trimming, but drastically improves case life, especially in those instances where the parent case has pronounced cartridge taper, such as in the .22 Hornet, .30-30 Winchester, .303 British, .30-40 Krag and .375 H&H. In such cartridges as these, case life is astonishingly improved.

Now, for the primary incentive for which most firearms are rechambered to the “improved” versions of various cartridges is the increase in performance. While in some cartridges such as the .270 Winchester, the actual yield is rather negligible, those cartridges that have the most body taper benefit proportionately better according to the increase in case capacity. Those same chamberings that benefit the most in terms of case stretch, also display the greatest velocity gains due to the significant increase in case capacity by straightening out their pronounced body taper.

While the increase in velocity is very real, and in some instances quite significant, the majority of claims regarding increased velocity are greatly exaggerated. Too, it’s apparent when looking over old loading manuals listing the “improved” cartridges, that the comparisons weren’t made comparing apples to apples. By this I mean that the pressures to which the improved versions were loaded, were much higher than those to which the standard SAAMI round were pushed. For instance, the .30-06 Springfield, when loaded to SAAMI specifications of 50,000 C.U.P., yields about 2,700 fps. when loaded with a 180 grain jacketed bullet. However, if you look at older loading data for the .30-06 Ackley Improved, you’ll see that same 180 grain jacketed bullet running out the bore of a 24” barrel at something just over 3.000 fps! The gain appears very substantial, until you also realize that the Ackley Improved version is also loaded to somewhat over 65,000 psi. This apparent gain comes with the price of increased pressure, plain and simple. In looking at some modern loading data for the .30-06 Springfield when loaded to its pressure potential in modern guns and new brass, such as found in the Barnes Reloading Manual Number Two, we find the 180 grain bullet pushed along to something over 2,800 fps with no less than six different powder combinations. So, looking at the old ’06 loaded to modern pressures, and comparing it to the “improved” version, while there is a difference, it isn’t nearly as dramatic as it might appear at first glance when comparing to loads at lower pressure standards.

It all comes down to simple math. You just can’t take a 3% increase in powder capacity, and turn that into a 10% velocity gain without turning up the pressure of the cartridge! However, there are cartridges such as the .30-30, .375 H&H, 30-40 Krag, .303 British and .22 Hornet that perform like thoroughbreds once given the Ackley Improvements. In these cases, the velocity gains are real, and of substantial increase, while working within the parameters of normal pressures, simply due to their more efficient form and increased capacity. Of course, as mentioned earlier in this article, these cases share the common trait of having radical case taper in their factory guise. All this is said, simply to make the reader aware that all claims regarding velocity gains aren’t as they might at first appear, and before making the plunge for the improved version, some research, and unbiased evaluation can be very revealing.

Now, as we look at the possible pros and cons of improving a cartridge, the factors of consideration don’t begin and end with velocity and case life. One must also look at resale value of the firearm if you ever decide to sell the gun; the market value is most generally slightly lower for an “improved” chamber gun, than one of SAAMI specs also they are more difficult to sell. Also there is the issue of reloading dies, as these can be very expensive to obtain, and in many cases are special order numbers with price tags reflecting that status.

Dies are the focus of this article, in the fact that not all, in fact very few of the Ackley Improved cartridges actually mandate a set of AI custom dies. In fact, most all of these modified cases can be loaded with a little ingenuity and resourcefulness using off-the-shelf dies!

In most instances, the Ackley Improved cartridges are found in turn-bolt rifles, and a few lever actions. This being the case, neck sizing of the brass is all that is necessary to obtain proper functioning in the firearm, and thus, full-length specialized Ackley dies may be avoided entirely.

Over the years, I’ve had occasion to own several Ackley Improved chambered guns, load for them and evaluate their performance. Too, being the frugal sort of individual that I am, I’m loathe to spend eighty bucks on a set of dies unless it’s an absolute necessity. So, mother necessity steps in, and American ingenuity takes over. A few of those improvisations are outlined below to help spark the imagination.

Not a great idea. Like driving a 20 ton truck over a bridge rated for 10. Would it work? Probably. However, bad things happen if it doesn't.

Besides the bolt, there's the tennon to worry about. Those walls get pretty thin and the lapua is not usually loaded to low pressures.

Also, if you're relying on the case head to hold several tons of white hot fire a few inches from your face, better make sure you don't have any like this:

You have to use the inside diameter of the case to calculate back thrust, not the outside; pressure only knows the area it is actually pushing against. Good example; adding a big rim, or even a belt, to a case does not affect the gross back pressure. And yes, brass does indeed carry much of the load, as long as it and the chamber are dry. Up to about 35000 psi; if you have ever seen backed out primers, well, that was the brass carrying all the load and transmitting none of it to the bolt.
Another note; when cases separate like shown in the picture, that does not usually release any gas back into the action; It is when the actual head fails that that happens.

quote:

Originally posted by dpcd:
You have to use the inside diameter of the case to calculate back thrust, not the outside; pressure only knows the area it is actually pushing against. Good example; adding a big rim, or even a belt, to a case does not affect the gross back pressure. And yes, brass does indeed carry much of the load, as long as it and the chamber are dry. Up to about 35000 psi; if you have ever seen backed out primers, well, that was the brass carrying all the load and transmitting none of it to the bolt.
Another note; when cases separate like shown in the picture, that does not usually release any gas back into the action; It is when the actual head fails that that happens.

Very well said!

quote:

Originally posted by dpcd:
You have to use the inside diameter of the case to calculate back thrust, not the outside; pressure only knows the area it is actually pushing against. Good example; adding a big rim, or even a belt, to a case does not affect the gross back pressure. And yes, brass does indeed carry much of the load, as long as it and the chamber are dry. Up to about 35000 psi; if you have ever seen backed out primers, well, that was the brass carrying all the load and transmitting none of it to the bolt.
Another note; when cases separate like shown in the picture, that does not usually release any gas back into the action; It is when the actual head fails that that happens.

The inside surface area calculation is how I was able to put a .220 swift in a 1891 Argentine DWM marked Mauser.

Math don't lie

But Me personally I would not install a .338 lapua in anything other then an 1.125-16 TPI threaded tenon or larger.

People get their panties in a bunch over the Lapua all the time. "well Remington put it in a standard action" How do you know it's a standard action?? Stiller uses a longer tenon and a larger thread.

Can you get away with it in a standard sized action?? Sure maybe But I don't want to find out.

A single shot Mauser action?? recent commercial Sure should work fine as the threads a 1.1"-12tpi so not a problem there.
the issue will be feeding it. and as much as i love a Mauser action and really despise a Remington, they and the clones have their place and suitability

Yes, Remington uses a standard action; 1 1/16th OD threads; not ideal, but not a time bomb either. Of course, a larger thread would give a better hoop OD, but that is not the issue as I see it; bolt thrust might be. Many people have built them on standard actions and I have not heard of a problem. As I said, the 338 RUM is a better idea and gives about the same ballistics; I own and load for both animals.

Although it is true that 416 Rigby's have been built on M98's (Selby) they strech the actions design, it should be stated also that the Rigby operates at lower pressures than the Lapua, in either case it is not a good idea, the only 98 type action suitable and easily available is the Brno 602 type, this action can safely contain the 338 Lapua. None of the military Mausers were designed for pressures of today. Commercial mauser loke the Parker Hale, Browning Safari etc. were designed for todays higher pressure rounds.
IMO
BB

quote:

Originally posted by ramrod340:
As usual just my $.02

Surely, that lot would have to be worth at least a nickel

quote:

Originally posted by dpcd:
You have to use the inside diameter of the case to calculate back thrust,

Na ha. That's why I put that "approximate" in those"DOG TRACK THINGYS". There are also a lot of other factors that make a difference too. You can think of the larger diameter as a built in safety factor to the math.

But it doesn't mater. Whats important is what ramrod340 said "Heck that is only 58% more."

Most people will agree that running a 30-06 at ultra high pressures to where brass flows can and will set back the bolt lugs. I would have to think that 100,000 PSI is pretty high pressure in a 30-06. That's double normal working pressures. Using the same program, this is what you get for bolt thrusts in a 30-06 at 100,000 PSI. Look familiar. It is within 1000 pounds of the 338 Lapua. That should tell you that the 338 Lapua is operating right on the edge of where normal actions begin to come apart. There is no safety factor left. If you fart when you pull the trigger the action is going to give.

100001 by Rod Henrickson, on Flickr

I personally would just buy a Savage in 338LM and be done with it.

Isn't that why Mauser made magnum actions? When I pour myself a cup of coffee I don't fill the cup so full it swells above the top. Instead, I fill it to 1/2" from the top. That way I don't get burned.