Does anyone reload for the 9x57 mauser? I would like to reload for mine, but I will be using .358 bullets for it. Where do I get the correct dies for the 358 diameter bullets, as a true 9x57 is .356, not .358? And does anyone make an expander plug to expand 8x57 brass to 9x57? Also, anyone have any load data for it? Thanks!!!!

I would just take a larger one and polish it down to the proper size.

ch4d will make you dies to resize .358 down .. fairly cheaply

I used to load 9x57. I used 358 Winchester loading data at the time. There's probably better published data around now.

358 Win dies will work to load the caliber too if you're not looking to FL size. Plus it'll expand to the .358d you're looking for.

That's what I used.
9x57dies were more than the rifle at the time, so a set from a gunshow table put me in business.

I never did slug the bbl and used .358d bullets right off. I was loading 35 Remington already so those (mostly 200gr) projectiles became my 9x57 bullets too.
Never had a problem but I always loaded on the very conservative side.

One pass over the .358 expander made 9x57s out of 8x57s. Nothing fancy there.
Lube the inside of the necks well.

Fun shooting caliber. Not a big shoulder bruiser, especially with my loads.

The 8x57 has the same dimensions except for the neck and the corresponding expander. You might know a machinist friend that can bore out a set of 8X57 dies.

Otherwise check some 8x57s cases in your rifle.
If they fit ok expand the necks and load. You can get by for a long time with just neck sizing in a .358 Win die.

My 9x57 has a rough bore, I've reloaded 358 bullets in it. Handloads that came with the rifle were 245gr RWS and 50gr 3031 but they are .355 bullets. I'm using a set of 9x57 Lyman dies and a .358 expander with Hornady 250gr and 44gr 4895.

Berdan primed



9th Ed., Cartridges of the World:

9x57 Mauser
9x57R Mauser

280 Gr Sp 43.0 gr IMR3031 = 2570 fps
280 Gr SP 46.0 gr IMR4064 = 2610 fps

You should be able to use the 280 gr loading for your 270 gr bullet.

I built a custom 9x57 using a .358 barrel.
I managed to find a new set of really old RCBS dies (came in a cardboard box) and use these with modern .358 bullets without issues.
I just neck up 8x57 cases with these dies without any extra steps or modifications.

Those above 280gr loads by richj correct but the velocities are incorrect. Not even a 9.3x62 will achieve those velocities.

My copy of cartridges of the world 6th ed has 280gr at a bit over 2000 f/s.

I have not gone anything heavier than 250gr bullets and using 52gr of Varget l get about 2350f/s

Yea. this is correct now

9x57 Mauser

280 Gr Sp 43.0 gr IMR3031 = 2030 fps 2570 me
280 Gr SP 46.0 gr IMR4064 = 2045 fps 2610 me

I am using RL15 in mine. I neck size with a Hornday 35 cal neck sizer.

Wonderful round.

I have a very nice 9X57 Mauser,octogon barrel,Mannlicher stock, and butterknife bolt. It appears to be original and was said to have been brought home by a returning soldier from WWII.

9X57 brass and dies from Huntington and a .356 swage die from Lee has made this a wonderfull little yard gun and loaded wih 42grains of Varget behind a 200 gr Hornady RN makes it shoot dead on to the sights at 75yds.

I'm sure it would be a fine moose round if needed.

Jim

byf42:

I use Redding dies for my 9x57. I just miked the expander ball: 0.356", exactly the same as for my RCBS 358 Win and 35 Whelen dies. The Whelen dies came with a tapered expander for taking 30-06 to 35, so I run 8x57 cases into that die just enough to expand the neck, and then finish sizing in the Redding die.

The groove diameter of my mid'20s vintage Mauser is 0.359", so using 0.358" works fine. I've only had the rifle a short while, so have only started load development, using Hornady 250 gr RNSPs with Varget. So far I'm up to 47 gr (ADI max is 49 gr), with velocity ~100 fps slower that Kynoch 245 gr factory loads in my 23.6" barrel.

Cheers, Al

You can get dies from Lee to squarsh (real word, uh huh) down the bullet from .358" to .356" or .355".

Fits better, shoots better.

I believe both Huntington Die Specialties and RCBS sell different sizes of expander balls for use in any size dies they sell.

I know I have LOTS of them which RCBS supplied to me gratis to expand the necks differently for my cast bullet loads and when making odd-ball cases from donor brass.

As to expanding case necks less than normal, I always take the expander ball assembly (without the decapping pin in place), chuck the assembly in a Makita hand drill, grab a bit of 240 grit cloth and hold it by hand on the fattest part of the expander ball. Then I turn the drill on.

I use my mic to follow how much it is reducing, and for the final 1/2 of .001" use 600 grit cloth to get a nice polish. Being a bit compulsive, I use a .0001" Starrett mic to creep up on the exact size I want, but a plain old el cheapo .001" mic is plenty adequate.

If I want an even finer polish I use a rouge polishing wheel on it as a last step. But the 600 grit cloth leaves a very fine finish which will hold just a wee smidge of lube in the metal surface.

No big technical thing, just a little slow handwork. Does the job just fine.

(And I can always get a replacement standard expander ball at almost no cost from whichever company made the original sizing die.