I'm thinking of doing a .300 Norma Magnum rifle with a Mauser action 1909. My question is if the diameter of the bolt allows that caliber and who sells barrels (in USA) chambered for this caliber. In addition, that twist I use with 180-210 grams. Thanks in advance, Hector

It uses standard .532 Magnum case heads, so yes, no problem in altering any Mauser 98 for that.
Use a one in ten twist.
No one will offer ready made barrels in this caliber as it is quite dead. You will have to have a gunsmith who has a reamer do it. Or some barrel bakers might have a reamer; check with them.
Or you buy a reamer.

massive headache to be done for zero gain over a mod 70 in 300 winmag -

a 1909 should be re-heatreated for a 60kpsi round

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It uses standard .532 Magnum case heads

I thought they were based on the 338 Lapua?

If so not something I would want in a 1909

The nice thing about 308 Norma, is that after you get tired of making brass for it, you can rechamber it to 300 Winchester or 300 Weatherby.

Just sayin.

quote:

The nice thing about 308 Norma, is that after you get tired of making brass for it

Is he asking 308 Norma or the new 300 Norma???

Big difference. I had a 308 Norma it was nice I built it to match my 358. 300 Wmag is sure a heck of a lot easier and cheaper.

Never heard of a 300 Norma; I assumed he wanted the old, classic, 308 Norma, which, as I said, is dead as a dodo; get a 300 Win instead.
If there is a new 300 Norma, then I have no idea.

I read that there is, in fact, a new beast called the 300 Norma, and it has a .585 head diameter.
DO NOT put this on a Mauser of any ilk. period.

I'm not to happy about putting that big 416 case in any convention sporting action. I know that it's been done to death, but 54 people per year jump out of perfectly good airplanes to their deaths for recreation too.

The question was for the .300 Norma, as someone recently called it "the beast". The Mauser 1909 and 1935 actions "treated" perfectly allow the pressure generated in these calibers. My experience is based on rifles in calibers these actions .300 WM; .375 H & H; .458 WM and one made in Europe by H. Mahillon in .416 Rigby, although not generate much pressure when using a large diameter sheath. And these rifles carry with me more than 30 years in use. Thanks in advance, Hector

While I wouldn't care for a 98 with a 416 Rigby in it to each his own. If a Rigby fits the bolt then the 300Norma would as well a Rigby is .5902 vs .585 for the Norma. Yes with heat treating the 1909 has been used for high pressure rounds.

Simply the case and action wouldn't be my choice.

Don't know anyone off hand making a pre-chambered barrel. Places like http://4-dproducts.com/display.php?group=Rifle rents the reamer.

Other than being different and losing the belt don't see the real gain over a 300Wmag.

Best of luck with your project.

ahh, the 300 norma - based on lapua case --

funny thing that, the guy that designed those cases is from the EXACT same town I recently moved from, Porter, Texas

about 10 years ago, when I was designing the AccRel rounds, I did do the .308 version -- never built one, as it wasn't anything like efficient and ZERO gain over a 30-378 except action length ---

yes, i did actually design the same thing, 5 years before introduction, and the designer lived in my same town of ~15,000 ...

and no way would i ever do this on a 1908. 1909, or similar action -- vz24? more than likely, 50s or newer commercial, sure.. but not a 1908/1909

Me either, and it always amazes me that there is any call for such over bore 30 calibers. If you want to burn a lot of powder, at least make it .33 caliber, and .375 is a better minimum. Anything over a 30-06, in a 30 caliber is a waste of components.
No hate mail, please; I get enough now.

The operating pressure of the cartridge doesn't scare me at all. It's the bolt thrust. The bolt thrust in cartridges that diameter is actually above the bolt thrust generated by proof loads.

But, it's not my circus, and they aren't my monkeys.

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The bolt thrust in cartridges that diameter is actually above the bolt thrust generated by proof loads.

Thanks Speer. For some reason I always forget that little fact.

Actually this idea was born to read the page Norma Factory which shows the potential of this cartridge for long distance shots, using a normal action and pipe 27". According to Norma yields between 200 and 300 fts more than a .300 WM, besides using spiked to 230 grs efficiency. Regards, Hector

quote:

Actually this idea was born to read the page Norma Factory which shows the potential of this cartridge for long distance shots, using a normal action and pipe 27". According to Norma yields between 200 and 300 fts more than a .300 WM, besides using spiked to 230 grs efficiency. Regards, Hector

Hector,
First let me say you should build what you want it is your rifle not ours.

Second if it were me and most of the guys here your action choice would not be ours. Not for a hunting rifle much less a long range target.

Third I think that is an excellent marketing line of BS (my 2 cent opinion) from Norma. I don't doubt that if you compare a 27" 300 Norma to a normal 24" 300Wmag you might get those velocity gains. Using a generous 1 for 4% gain for capacity you are in the less than 100fps gain area.

Forth yep QL is only a tool. But looking at a number of heavy bullets in both at same pressure and 27" the gains CALCULATE in the 80-90fps range.

As I said I sure hope it works for you. Hope you can build it and come back and say we were full of crap.

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Just for interest.

The odd thing with cartridges is that as you make them bigger you eventually reach a point of diminishing returns where you actually have to begin to make them A LOT BIGGER, to see any significant increase in velocity. This is partly due to the availability of specialized fuel components, but mostly to the size of the piston in relation to the bore length. In the .308 caliber the 300 Winchester is actually that mile marker. It's obvious that Norma had to do a whole lot of cheatererering to get the modest 200 FPS increase over the 300 Winchester. The first of course is about 11 grains in weight of water, more case capacity than the 300 Winchester which came at the expense of increasing the diameter of the case from .532 to .583. The second, as noted is the huge increase in barrel length. What a lot of people don't realize is that they also had to increase the operating pressures from the standard 54,000 CUP of the 300 Winchester to a staggering 63,817 CUP. Almost a full 10,000 CUP over the standard belted magnum. To do this they had to take a page out of Lapua's book and make the base of the case extra hard so that it would hold together at those pressures. As far as the barrels go there is more than enough hoop strength and the actions and barrels in all guns are tested with proof loads at 70,000 PSI. But neither are made to operate full time at those pressures. While the pressure on the barrels is still barely under proof loads, which is questionable. The bolt thrust, due not only to the increase in pressure, but also to the increase in case diameter is not. The bolt thrust on the Norma actually far exceeds that found in proof loads. While the lugs are certainly not going to just sheer off. There is a very high risk of them setting back slowly over time or galling from repeated hammering. Owing to the fact that the operating bolt thrust has already eaten up most of the safety margin in the system, if something was to go wrong, you are already very close to the point where very bad things will begin to happen.

Like I said. It's not my circus and they aren't my monkeys. Govern yourselves accordingly.

300 Norma Bolt Thrust Comparison by Rod Henrickson, on Flickr

You could have someone turn the case heads down to magnum headsize, then thrust would be no worse then a 300 win mag. 50 cases done would last a lifetime for a specialized hunting rifle.

Shouldn't you square the radius, not the diameter?
Then ad 17152 to chamber press?
I thought bolt thrust was less than chamber press, or is it more in .585 cases?
Thanks.

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That wouldn't work theback40. It's based on the piston size. Not the rim size. It should actually be based on the inside diameter of the case not the outside. The formula is actually only an approximation but is accurate enough for our armature uses.

I'm not sure where I got the formula metal. I suspect it probably came from Hatchers Notebook. Wikipedia shows the bolt thrust for the 300 Winchester to be 12,640 lb which is close to what I got. The values are approximately correct so I suspect the algorithm is correct.

Metal "I had a typo it should say radius squared not diameter. I just dumped the formula into Excel and made notes to remind me how the formula worked. The algorithm itself is correct"

The formula is shown here:
https://en.wikipedia.org/wiki/...culating_bolt_thrust

Ok, that is more confusing than necessary. And that Wikipedia article is very confusing, and misleading.
Yes, you use the inside case diameter; the chamber pressure does not know how big the rim is. And you square the radius of that, multiply by Pi, and multiply that times chamber pressure. You will get a value in pounds of force against the bolt, with an oiled case. Recognize that cartridge brass, dry, will absorb at least 30000 psi by itself with no bolt help.
Still, this is too much for a Mauser, for me.

So the bolt thrust of the 300 Norma is 17152 Foot Pounds or PSI?
thanks

It is neither, but the value would be in pounds of thrust against the bolt face. Everywhere inside the case is the same chamber pressure in Psi, but only a very small part of that is exerting pressure against the case walls. And the base, inside of the case. Not the outside; the pressure can only act against the inside. That number, 17162 pounds, is invalid.

Paul and Speer, your answers are lengthy, complex but very interesting, let me think that this choice of gauge can be inconvenient and that I should go, for faster and use more weight tips, to another caliber. 300 NM offers many difficulties to assemble a rifle and then reload your ammo. Continue to study alternatives and tell them when you have a decision. First of all, thanks to all the forum participated by time and the interest they have shown me. Best Regards, Hector

in a hunting rifle, say 24" barrel and less than 10#, there's no MEANINGFUL difference in a 300winmag and a 30-378w or 300 norma...

you can't shoot 500 meters off hand, requires a rest, and with a proper stock for this, the caliber isn't important

and 3-4" longer barrel matters

Speerchucker is right; it's the piston diameter, not the rim or belt. I don't claim to know what I'm talking about most of the time, but I HAVE had some physics and engineering beat into me over the years.

To clear up the confusion;

Speerchucker's formula is correct but the text is in error. It is the radius of the case head diameter that is squared in the formula not the case head diameter as the text says. After all the diameter has been divided by 2 which gives us the radius of the case head circle which is then multiplied by itself (squared).

All the formula is doing is is calculating the area of the case head in 'square inches' and then by multiplying that decimal fraction by the chamber pressure, which if it is in lbs per square inch. gives us the total lbs of thrust against the bolt face (not PSI).

If the chamber pressure was in kilgrams per square inch then the answer will be kilograms of thrust.

Don't get confused with the diameter of a piston in this case, this doesn't really apply to a case as it is not a uniform diameter inside therefore it is the overall case head area that is transferring the chamber pressure thrust to the bolt.

The British proof pressure for the 300 H&H is 18.5 Long Tons/PSI measured as actual thrust against the bolt face with a copper crusher and special bolt head.
Converts to 41439 PSI.
Cheers.

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OK OK OK I changed it. Damned grammar Nazis !

LOL

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For what it's worth, bolt thrust is just a number. But it's a number that can be used to compare scenarios to give us a close approximation of what will happen when those numbers are reached. There are accepted levels of bolt thrust which will cause no damage over thousands of repeated firings and there are levels which are known to cause damage to the firearm or possibly to the shooter.
In the first big shop I worked in, the owner hashed out a deal with Remington Arms to extend our warranty service to include the installation of barrels, receiver bodies and bolts. This is something that Remington had never done before but the problems that they were beginning to have getting guns over the Canadian/USA border for warranty work were getting unbearable. Part of the agreement was that one of our people would have to go to Ilion NY to the plant to take a course in proof house operation and whatever other warranty courses they offered at that time. I was the one that was sent down.
The courses were about as dry and boring as any other armorers course you can imaging, but part of the training was hands on and another Canadian and I were basically given free run of the plant (with an escort of course). In the proof house area we went through all of the required hands on and while I was in that part of the plant I candidly asked the foreman: "At what point a Remington 700 would actually blow up?" Like a lot of my other liability related questions, the guy just gave me the politically correct, bovine stare and moved on to the next part of the program. Oddly enough, after about a full two minutes and while continuing to do whatever he was showing to us, he candidly and very carefully said: "At 80,000 copper units of pressure in any cartridge, the vessel in the cartridge array will begin to flow into the bolt head extractor ring and ejector plunger port. At 100,000 copper units of pressure in a belted magnum, the steel in the receiver array will begin to move in a permanent manor."
So, if you wanted some guidelines to go by as to the maximum bolt thrusts that you can play with. Those would probably be the most concrete and reliable numbers that I could give you.

Belted Magnum Dangerous Pressure by Rod Henrickson, on Flickr