Discussion in 'Up To .375' started by BrokenArrow, Aug 12, 2017.
Looks like a river that you might NOT want to go wading in.
Unfortunately, most of the loads posted are very conservative due to the older small ring Mausers out there. Right now I'm running my Mauser with 47.7 grains of IMR 4350, almost two grains above the published maximum. No signs of pressure whatsoever and excellent accuracy.
I find a comparison of the loads listed as maximum to be interesting. Consider the two parent cases: 308 Win & 7x57mm. When necked down to .243" the loads for the 243 Win are less than the 244/6mm Rem by nearly 100 fps; but when necked to .284, the 7-08 is less than the 7x57 by 100 - 200 fps. Appears they are imposing pressure limits on the 7x57 that are not being placed on the 7-08. So provided one has a rifle suited to the higher pressures, it does appear that the 7x57 is quite suited to higher performance than some loading manuals indicate.
Both the factory ammo and max load data is intended for the weakest of the various firearms that have been chambered in the 7x57- not only some of the early Mauser bolts but also the rolling block. That reduced pressure standard also applies to other similar older carts/rifles. The OP was very clear in wanting to find a temperature insensitive load for reliable function in high temps with the 160 gr Nosler AB. More interested in accuracy than the last 100+fps of potential velocity. A very wise approach IMO!
I used to load the 7x57 for my wife's Ruger bolt gun for hunting specifically elk and mule deer. My load was a modest one- the 150 gr Nosler Partition at just over 2500 fps. I will guarantee that combination was an extremely efficient killer. I should know as I had to help pack out a bunch of them on my back. The OP's load of 2400 fps for the 160 gr Nosler Accubond should be perfectly adequate for the plains game intended.
Hey guys. Thank you for your comments. A question.
Is the M98 Mauser action regarded as a strong action? My rifle is built on a DWM action made sometime between 1935 and 1942.
The M98 Mauser is considered a modern action and is a strong action. It's the 95 and 96 small ring Mausers that are problematic, they can't tolerate PSI of more than 45,000.
Really, from the Mauser 91 throught the Mauser 96, German or Swedish made, in good condition, can be used with modern pressures 7x57. I am refering to 30-06 and including 308 Win factory loads pressure type.
By the way the late Hirtemberger factory loads, and the past and present NORMA and RWS factory loads are full power loads. And those factories never discriminates the Mauser model rifles their ammo were for...
And even some of the military 7x57 ammunition were full pressure loads.
I used for years, and still use, in my DWM 1893 Factory Sporter, the same loads as in my 1935 Mauser. And they are full power SAFE MAXIMUM loads.
European 7 mm cartridges all have 7.24 mm (0.285 in) grooves diameter. American 7 mm cartridges have 7.21 mm (0.284 in) grooves diameter.
According to the official C.I.P. (Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives) rulings the 7×57mm case can handle up to 390.00 MPa (56,565 psi) Pmax piezo pressure. In C.I.P. regulated countries every rifle cartridge combo has to be proofed at 125% of this maximum C.I.P. pressure to certify for sale to consumers.
The SAAMI Maximum Average Pressure (MAP) for this cartridge is 51,000 psi (351.63 MPa) piezo pressure or 46,000 CUP. Although this lower specification is in deference to the purportedly weaker actions of the older Mauser 93 and 95 rifles which are still in circulation, this concern is misplaced, as the original ammunition developed for, and issued with, the M93 Spanish Mauser produced an average pressure of 50,370 CUP in those rifles
Not sure if you mean that you can load a 7x57mm to the pressures of a 30-06 and 308 Win with below statement. If so that would be a foolish thing to do.
I am refering to 30-06 and including 308 Win factory loads pressure type.
The maximum operating pressure for a 30-06 is 60200 Psi(415MPa) and for 308 Win 62000 Psi(430MPa) whereas the maximum for the 7 x57mm is 56565 Psi! Factory ammo is set at 51000 Psi. which is very far from 308 Win or 30-06 pressures.
Mauser’s original design specifications call for maximum average pressure of 49,313 Psi using the copper crusher method. That translates to 56,565 Psi if measured by means of the modern piezo transducer method as measured in terms of the CIP protocols. In SAAMI’s American conformal measurement system parlance the Mauser specifications are set at 46,000 CUP or 51,000 Psi. When becoming puzzled by the different pressure levels specified at different places, always remember the difference in measuring techniques used by America and Europe, as well as the differences between crusher and piezo determined results. The same cartridge can therefore have have at least three different psi pressure levels.
Current thinking consider these pressure specifications on the low side, but it pays to rather be safe than sorry. Obviously commercial ammunition is loaded to these moderate levels in order to conform to the standards specifications and to avoid litigation.
Bear in mind that the 7mm Mauser built its enviable reputation at the moderate velocities resulting from such moderate pressures.
Re-loaders can improve on the 7x57mm ballistics but if you are looking at much higher velocities or pressures, switch to a larger case capacity cartridge such as the 7 x 64mm Brenneke instead of pushing the limits with the 7x57mm.
In my opinion it is the greatest plains game caliber for Africa ever made(since 1892), it was my first choice when I bought my first rifle and I have used it ever since.(so have my daughter and son).
Use it within it's design specifications and you have a wonderful cartridge than will kill most things you point it at with much more authority than its paper ballistics ever could suggest.
Well lvW. You are right! It pays to rather be safe than sorry. So, anyone who want to load the 7x57 above its standard pressures is on his own and this cannot be recommended !
I agree! I have never yet had an animal I hunted complain that the bullet was travelling too slow. But I have seen a bullet that would have complained if it could, that it was travelling too fast!
The common comeback here is 'at what stage of the animals death did it fail?'
I want to trust that my less than ideal shot will reach the vitals. Slower impact velocity's achieve this in my opinion. Plus it is easier on you, the gun, brass...
Yip and in the case of the 7x57mm if you use premium 170-175 gr bullets you can kill darn near anything with it and enjoying low recoil and much better shot placement as a result.
My 7x57 (DWM 1908 custom) liked the 160gn Woodleigh PP bullet at 2700fps and to me that is an excellent load for just about anything anywhere in the up to medium heavy PG sized animal.
I also use 154 to 175 grs bullets in my 7x57s.
IvW has just made me question something else about this caliber... When a 7x57 is 'barreled' i.e. barrel measurements to European specs. Is it bad to shoot .284" or smaller bullets through a .285" barrel? Does the barrel get damaged by 'hot, high pressure gases getting past between the bullet and barrel? I am aware that lead core bullets may obdurate, do copper/monolithic bullets such as the Barnes TSX cause damage?
I tried some mono-copper bullets in mine and the lands fouled badly, and yet there was absolutely no copper fouling in the grooves! I measured the bullets and they miked out at .28380"! Shot well for about six shots, then 'something' went wrong...
Thanks again for all of your opinions. Tomorrow is the final test day...!!!
I like the Woodleighs, great bullets for the 7x57...in the 160 and 175 grain form!!
The 1896 6.5 x 55 Swedish Mauser was proofed at 64,000 psi. It is a very strong action and therefore a handloaders dream.
Jack O'Connor's load for his wife's 7x57 was a 160gr Nosler partition over 52grs of surplus H4831. Velocity ran just shy of 2700fps. With today's H4831 I'd drop down 10% and work up. This load is perfectly safe in any modern strong action. I used it for years through an old Ruger tang safety 77 and killed everything in my neck of the West including elk. As to H4831 regular or SC I've used the same data for both interchangeably without problem. In fact I prefer SC as it settles into a case much easier when working up full power reloads.
My favorite load for my commercial Fn Mauser 7x57 is
Somchem S365- 44grns
175 Hornady RNSP
This is a soft and accurate load in that particular rifle and punches way over its weight in the field. I use it exclusively in the bushveld
7x57 ? I'd think about it one more time.
Tuli Block in Botswana is elephant country,Ive been there last year .
Elephants almost everywhere.Massive herds.
A .458 would be a safer walking cane for me.
@BrokenArrow Every '.308' bullet that I have ever measured has been .307.5 inch maximum outside diameter. The only time you are likely to find one fatter than that is when you get a special oversize bullet made for NRA shooters to prolong the accuracy lives of their barrels. German .323 inch military bullets were designed to be shot through 8.22 mm (.324 inch) barrels. The Vz 33 and G 33/50 rifles have a 7.88mm bore diameter and a 8.28mm groove diameter for use with the sS 198gr bullet. In other words, not a problem.
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