Home Forums Reloading Big Game Rifles 7x57- Opinion on a load aka am I going to blow myself up?

Hi Gents
I've been loading for a 7x57 of some flavour for many years and always loaded 140-ish grain bullets.

I'm now loading fro a Brno 21 small ring mauser made in 1950 (square bridge)

I was recently gifted a metric-poop ton of 150gr Winchester power points (a Jam-jar chock and block full) and about 300 154gr SP's.

I've usually loaded to 7mm-08 velocities in large ring Mausers and never had any issues.
I've never loaded for a small ring and do not know if they are as strong as large rings?
However if Brno chambered the Mod 21 in 7x64 then the action should be fine with 7mm-08 equivalent loads for the 7x57 or is my logic skewed?

Looking at Nosler's data they list 48.5gr H414 with a 150gr bullet as their max load for the 7x57
But they list 46gr of the same powder and bullet for the 7mm-08
That 48.5gr load seems very stiff to me given that it's 2.5gr more than the max 7mm-08 load.

I've fired 48gr's in my Brno and the bolt lift was not stiff, cases did not stretch a whole lot and the primers did not seem flat to me.
Accuracy wasn't too bad, good enough to hunt with but I'm concerned about firing such a hot load in my rifle long term.
Do you think I'm playing with fire here or do you think I'm safe with a 48gr charge of H414?

Cheers!

7x57 cases hold a lot more powder (about 7%) than 7mm-08. So an equivalent pressure between the two with the same bullet is going to require more powder in the 7x57 cases. I think you're fine. About 5.5% more powder doesn't seem outside the norm, given that that the powder is on the slower end for the case. Another thing to consider is that though 414 and 760 are the same powder, Nosler's max for 760 and 150's in the 7x57 is 46gr. So you are looking at differences in powder lots, basically, which can be as much as 5-6% for ball powders like these. If the cases look good, shoot away.

I`ve a 91 in 7.65. Small ring. I shoot mid range reloads with no worries. You could do the same in your rifle.

That’s what I thought too but I was nervous about it.


I’d be happy to shoot mid range loads, problem is the rifle shoots the hot loads bloody well.

I own a few 98 small ring Mausers of different persuasions, including 2 Brno 22s. Although I have never loaded above max loads in any rifles, I have been curious about the strength of the small ring 98s. While discussing Mausers with a gentleman from Germany who has forgotten more about them than most people know, I asked him about the combination of large and small ring 98s Germany used during WWI (you'd be surprised how many SR 98s they used) and the ammo they used in them. He said that the common German issue 8X57 was used in both with no concern about the strength of the small rings. Considering how hot the Germans loaded their 8X57, that speaks well of their strength.

Since that conversation, I have not distinguished ring size whatsoever in my loading. Be reminded that I do not load ANYTHING I own hot (especially old mausers) and never have. But, I do use the same loads in 98 Mausers regardless of ring diameter.

Great info thank you.
I compared load data in the Speer manual that I have and it's really not far off from the data that Nosler has.
Makes me think that 48gr of H414 with 150gr bullets should be fine.
Even though It seems the load will be fine I'd still prefer not to load real hot.
I'm going to try IMR4350 and see if I can get a load to shoot with it that's not quite as hot.

As HuntnShoot explained it.
Case capacity is greater for the 7x57 and so it takes more powder to reach the same pressure levels.
Les

Hodgdon shows 44.5 grains of H414 as max, at a pressure of 45,400 CUP. What pressure is safe in a small ring Mauser? Can’t base it on German “high pressure” military ammo, that was loaded to just 43,511 psi in WWI ( https://en.m.wikipedia.org/wiki/7.92%C3%9757mm_Mauser ). A modern post-war Chech rifle in good condition should be safe at reasonable modern pressures.


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Interesting DR, I have always read that there is no way to correlate psi and CUP in any given cartridge without actual lab testing. I wonder how 43,511 psi would compare to 45,400 CUP in the 8X57?

I certainly agree that a post war Chech rifle is good to go. At least I hope so, because I load my 22F 7X57 at modern pressures/velocities, or at least just under max. A second 22F in 8X57, received just this past Saturday, will be loaded similarly.