I am a fan of the A3-O3 Springfield and the 98 Mauser action. I have access to a 1944 Mexican Mauser action that I am thinking of barreling to a nice 30-06 barrel that I have from another project. But, I don't want to make a mistake. Can anyone give me some useful information? Happy New Year!

Being a short action, the 06 will be a bit long. Not a good choice...308 would fit nicely

The original 7x57 would be my choice.

I'd go with 275 Rigby...

DPCD what barrel twist rate and throat length differences would there be from a 7x57? And any other differences?
Stu

Rigby vs Mauser

https://www.africahunting.com/...57-ammunition.66585/

There are no differences; it was a joke.
Just make sure you get the throat made for the bullet you intend to shoot; IE, I have two reamers; one for 140 grain and one for 175..

I also have two reamers same as dpcd...However, the shorter throat version is almost never called for..most want the letttering to say "275 Rigny" but throated for the 175 gr,

The resonsible smith will letter "275 Rigby 140 grain " if the shorter throat version was actually chambered.

The situation simply produces more words

When I was working with my .275/7 mm rifles, I was surprised to learn that there is a significant difference in throat lengths between the ones named .275 Rigby (British origin) and those named 7x57 (German origin).

The throat length of the 7x57 mm is over three times longer than the .275 Rigby's throat!

.275 Rigby HV CIP Dwg.: Throat Length = 5.65 mm (0.2224 inch)
7x57 CIP Dwg.: Throat length = 19.2 mm (0.7559 inch)

That can make it impossible to load 7x57 rounds with heavier bullets (from 150-175 grains, depending on bullet profile) in a .275 Rigby chamber.

Barrel twist rates are different as well, but not so as anyone would notice.

.275 Rigby HV CIP Dwg.: 1 turn in 203 mm (8 inches)
7x57 CIP Dwg.: 1 turn in 220 mm (8.66 inches)

I have found that these differences hold true in the .275 Flanged and the 7x57R as well.

There is the potential problem of ammo headstamps not matching caliber stamp, at least in Africa. For the last one I had built the smith asked how I wanted it stamped. As cool as .275 Rigby looks/sounds, I stuck to 7x57.

I do not follow CIP drawings; (zero reason to do so), nor do any of my clients. And they all want the 140 grain throats. Rarely the long one. Who the hell would want a 3/4 inch long throat? And where does one get an 8.66 inch twist barrel; don't care anyway.
As for taking them to Africa; not my problem.
I use only 9 inch twist barrels for 275 or 7x57; again; don't care what they originally used.

quote:

Originally posted by squeezenhope:
There is the potential problem of ammo headstamps not matching caliber stamp, at least in Africa. For the last one I had built the smith asked how I wanted it stamped. As cool as .275 Rigby looks/sounds, I stuck to 7x57.

Rigby mark their Highland Stalker barrels with both calibers, but actually chamber the rifles for the .275 Rigby HV round and mark the chamber on top of the barrel with "Sighted For Rigby's Special High Velocity .275 Bore Cartridge Soft Nosed 140 Gr. Bullet."

But as I say, the rifles are more than just sighted for those cartridges, they are chambered for them as a matter of standard practice, notwithstanding the 7x57 dual marking. How they can mark them 7x57 I don't know.

I had them chamber mine for 7x57 since I want to be able to shoot any bullets I may choose. All markings are the same as their regular rifles.

I have been able to find plenty of Hornady brass and ammunition with the .275 Rigby headstamp.

It is of excellent quality.

A question about the cartridge OAL limit with the shorter throat and a representative spritzer bullet like the Nosler BT or Partition?

ClaMar

You will have to load one to the length you want and then have it throated for that. It depends on the ogive shape.
As for caliber markings; if someone wants it, just mark for both calibers as indicated above. The chambers are the SAME! Throats are different from the original Rigby and Military chambers with throats made for the long 175 grain FMJ bullets. But throats, are not chambers. However, if you get the long throat, then your 140s will have to jump like a half inch. Is that what you want?
When my clients want heavy bullets, they order bigger cartridges. 7x57 is too small for 175 grainers. No more hate mail please.

SAAMI does not care about throat length other than for pressure test barrels. Production barrels can have whatever throat the manufacturer wants to put in them. Order a 30-06 from 3 different manufacturers and you will get 3 different throats. Throat length has way more to do with bullet nose ogive shape than it does bullet weight. And how much magazine length you have. Today everyone wants long nosed VLD bullets with plastic tips because modern deer and elk have better eyesight than they used to and they wont let you get closer than 800 yards so you need to shoot them way out there. Even the heaviest bullets do not need more than about .200 freebore because the tip of the bullet is 5 miles in front of the start of the bearing surface of the bullet. I guess if you have a 7x57 on a full length action you could seat them way out there but in that case you might as well chamber for 280.

It is the old 223/5.56 thing all over again.

John

Just my opinion..but "special throats" now put the cartridge in the category of a wild cat and should be designated as such.

Simply a responsible thing to do since someday the rifle may fall into other hands.

CIP and SAAMI is the standard we are obligated to adhere to.

Hndloaders can go ahead and "fit" the bullet(s) to those standad acceptable chambers

quote:

Originally posted by Duane Wiebe (CG&R):
Just my opinion..but "special throats" now put the cartridge in the category of a wild cat and should be designated as such.

Simply a responsible thing to do since someday the rifle may fall into other hands.

CIP and SAAMI is the standard we are obligated to adhere to.

Hndloaders can go ahead and "fit" the bullet(s) to those standad acceptable chambers

Gas gunner.....lot of wisdom but then...why are specific dimensions shown for throats..OK admittedly SAAMI is "voluntary"...Give that. But for a gunamith to adhere to puiblished standards puts that gunsmilth in a pretty sdound defensible position

We don't give a damn about Sammy, whoever that is. We are not obligated to adhere to anything. And unlike other countries, we don't want to be.

Gas gunner.....lot of wisdom but then...why are specific dimensions shown for throats..OK admittedly SAAMI is "voluntary"...Give that. But for a gunamith to adhere to puiblished standards puts that gunsmilth in a pretty sdound defensible position[/QUOTE]

They specify throat specs for pressure test barrels so that you have uniformity in pressure testing. Production throat specs are all over the place from one manufacturer to another. Everyone thinking they have a better mouse trap. Not to mention reamer wear and resharpening in a production environment will lead to significant variations even within the same manufacturer. Also within reason, throat dimensions have very little effect on pressure. Please do not take that to mean you can put a weatherby cartridge designed for a mile of freebore and put it in a chamber with .100" freebore and not have any issue. You likely will. But changing the freebore .025" here and there or changing the lead angle a degree is not going to have a significant effect on pressure. Proven that plenty of times here. If you run into pressure problems because the throat changed .040", you were way overpressure already. And that is on the little cartridges that I play with where small changes can have a bigger effect, and standard loading practices are to add powder till the primers fall out then back off a half.

But we all accept a certain level of risk, and have to make that decision based on our own experience. I'll be the last to tell someone what they should or should not do in their shop. Plenty of stuff I say no to, and no amount of wining or throwing money around from the potential customer is going to change that.

John

quote:

Originally posted by dpcd:
We don't give a damn about Sammy, whoever that is. We are not obligated to adhere to anything. And unlike other countries, we don't want to be.

Right way,. wrong way, army way? havitchurway

SAAMI specs are for factory rifles, chambers AND ammo! No one here is mass producing rifles for the untrained casual shooter and hunter. For those, sure, he needs uniformity. For AR members, they specify what they want.

So sorry...Had no idea you had your finger on the pulse of all of AR.. well...back to cubuts, leagues, etc..What a perfect world,. we can all determine out own unit of measurement.

tejas -
Wannna get crazy and do something unique with your Mexican? Got a top tier gunsmith to chamber and fit a NEW .308 barrel and widen the feed ramp if needed? An '08X57 would be way cool.

I have hunted with and built a number of 7x57s and 275Rigbys with a 7x57 Reamer as have many others, and there is no difference that I am aware of..I always throated mine with the 160 gr Nosler seated out to match the magazine and the throat..they always shot the 130 grs Speer and the 160 Nosler very accurately and the 175 gr bullets shot around an inch..Rigby or 7x57 used 7x57 Rem or Win brass. My latest is a RJ Renner and it is the usual 1x9 twist long throat and shoots any load under an inch most of the time..

My Renner or my Ruger will shoot a 175 gr bullet at 2600 fps in the long throated versior, My 30-06 shoots a 180 at 2600 FPS in my guns and both could handle 2700 fps..so why is the 175 too heavy for the 7x57? Someone is baffling with BS.

The Europeans do things a bit differently.

The throat (or Commencement of Rifling, as they call it) dimension is specified for each caliber of firearm approved by the CIP and listed in their Tables of Dimensions of Cartridges and Chambers.

It does ensure that specific calibers of cartridges, no matter the weights and profiles of their bullets, will in fact fit correspondingly chambered firearms.

Not an altogether bad thing.

And it corresponds with the extreme control over all things shooting related; something we DO NOT want to happen here. Of course the Governments in Europe dictate, and test for compliance, Everything related to shooting sports. We have enough control by government now over our hobby!!!
So, definitely a bad thing. They can keep it and all controls over anything shooting related. We are fine as is....

Having seen and suffered the work of some so-called gunsmiths, I might be inclined to disagree.

On a case-by-case basis, of course.

Hi,

The ONLY differences between Rigby 275 High Velocity marked rifles and the normal ones were the sighting regulations!
Rigby bought barreled actions from Mauser. Mauser barrel chambers for the 7 mm Mauser had only one standard dimentions from the cartridge start: 1:222 mm for rifling twist and Commencement of Rifling distance-throat lenght, of 19,2 mm, like CIP standard.

quote:

Originally posted by PatagonHunter:
Hi,

The ONLY differences between Rigby 275 High Velocity marked rifles and the normal ones were the sighting regulations!
Rigby bought barreled actions from Mauser. Mauser barrel chambers for the 7 mm Mauser had only one standard dimentions from the cartridge start: 1:222 mm for rifling twist and Commencement of Rifling distance-throat lenght, of 19,2 mm, like CIP standard.

Perhaps true in the past but no longer.

Today's Rigby Highland Stalker is marked .275 Rigby H.V./7x57 but is made with the CIP standard throat for the .275 Rigby H.V., which is 5.65 mm in length.

Unless, as I say, one asks for the CIP standard, 19.2 mm long 7x57 chamber, in which case they will accommodate your request.

The latter is necessary if one wants to shoot any number of bullets weighing from 150-175 grains.

Good information Mike...Hope others on thread take that in the spirit which it was intended.

WOW, 5.65 to 19.2 mm is a huge difference. That will have an effect on pressure. Is anyone shooting the long heavy round nose bullets anymore?

John

No, no one I know has any use for the long 175 grain military type round nose bullet. And they won't fit into the short throats anyway.
As for CIP twists and throat lengths; who cares? They do not apply here. Maybe if you are in Europe, but in much of the world, handloading is highly regulated, or banned. Governments do not want the common person to do such hazardous, and potentially deadly, activities.
I will make your throat, and you can make your ammo, any way you want it. In the US. No Government intervention needed.

OK..we get it!

Most but by no means all factory loadings in the 7x57 use 139 or 140 grain bullets.

Several manufacturers, however, including Federal, Sellier & Bellot, HSM, Norma, RWS and others load 150, 156, 160, 173 and 175 grain bullets in the 7x57.

Chiefly for use in hunting large game.

quote:

Originally posted by Duane Wiebe (CG&R):
OK..we get it!

We do, but somebody always has to have the last word.

Well....not my intention to "Have the last word" I have been in touch with a friend and shirt tail relative in Sweden, makiong inquiry abut the 7 x 57 in use there.

Synposis : 7x57 is in use there, not as common as 308, 30-06 and of course 6.5 Swede. The 140 gr 6.5 is the minimum legal load that can be used on mooose and bear . The 7x57 is totally adequate (and used) , with the 175 gr bullet the most favored. He noted the 7x57 R is more common.

So...yes...the 175 gr load is in use

EArly on with the 7x57 I shot only 175 gr factory ammo and never felt short on the many deer and antelope I shot on the family ranch, guess I just didn't know better, but it about equaled the 30-30 and I never felt short with a 30-30..MY first 7x57 was a milsurp mod 95 Mauser, well worn but accurate even with iron sights. Those were the days!!

RAy...I'm guessing you m ight have done a bit of stalking...for the folks unfamiliar with the term, it sneaking up as close as practical to place a humane shot

Helluva a lot more fun than launching bullets at 800 yards!

I admonished my grandsons that the only thing better than a 100 yard shot is a 99 yard shot

Duane, so far I have killed three red stags with my 7x57R using 175 gr. Nosler partition bullets.

You will be happy to know that we stalked all three of them!

Thanks.... Mike. Happen to have any photos readily available? Any down side to using ammo that "nobody uses anymore"

What rifle did you use?