I have the chance to buy a beautiful octagon barreled M98 custom rifle. The caliber is 9x57 Mauser.

I love .35 caliber guns and this is only the second bolt gun I have ever seen in this caliber.

The question however is reloading for it....according to Cartridges of the World the groove diameter is .356 same as a 9mm pistol. It goes on to say that .357 and .358 bullets can be resized to fit...

Some questions to you who have reloaded for this round are:

Have you ever loaded .358 bullets in this caliber or did you have to custom order .356 bulets?

If .358 bullets were used or tried, was the cartridge able to chamber with the cartridge neck expanded .002 over what a it would have been with a .356 bullet.

Have any of you ever resized bullets to make a slightly smaller caliber? What was required...a Corbin press and dies?

Any other information on loading this cartridge would be appreciated. It is a very nice rifle and if it can be easily reloaded for I would love to buy it....

Bob

All you need is a 7/8-14 threaded and heat treated die that has a .3585 lead and a .3555 neckdown and well polished.

There should be no trick at all to push a .358 bullet (well lubricated) thru the die using a pusher fitted to the shellholder using almost any decent press such as a rockchucker.

I think there is someone that makes them but almost any machine shop will make them as well.

Even custom made they might run about $200 for the set.

I have no interest in the caliber but if I wanted it as bad as you do, I sure wouln't let the bullet availability stop me. Necking them down .002 should not be a problem.....especially the pistol bullets.

.

Slug the bore to discern what its diameter is before taking any action. You may just be able to get away with shoot .358's without any extra work.

First off, I have zero experience with the 9x57. I can only offer armchair advice. That said, a couple of articles I have read about the 9x57 mention that groove diameter can vary. One article was in The Accurate Rifle magazine (no longer published). The author found that his 9x57 did indeed have a.358" groove diameter.

The other article I read was in African Hunter magazine. It's online here:

The 9x57 Mauser
http://www.african-hunter.com/9x57_mauser.htm

Excerpt:
"The correct bullet diametre is .356", whereas American bullets are .358". However, American bullets can be swaged down (or put on a centreless grinder) and thus made to work. Before doing this, I would slug the bore of my particular rifle to find out the exact groove measurement, as a lot of these older rifles can vary considerably in their bore dimensions. You may well find that .358" bullets can be used as is. You may equally find that further reduction is necessary, however!"

So I agree with Tex21. If possible, slug the bore to determine the rifle's actual groove diameter.

My two cents....
-Bob F.

Thanks for all the responses...one minor confusion. One of the articles I read said that the round was based on the 8x57...did that article mean to say 7x57? In the Cartridges of the World book the round looked to be a necked up 7x57...the 8mm Mauser is a 30-06 size case as I recall.

The gun is very beautiful...I have no clue where it was made, Europe or England. Looked like a 26" octagon barrel, turned down bolt, Pecar German 3-9 scope in German QD lift and twist off mounts..flip down single rear blade sight, double set triggers...nice wood in about 95% condition...they want $650.00 for it.

Would like to see what the bore diameter is before I get it home...

Bob

quote:

Originally posted by RJM:
Thanks for all the responses...one minor confusion. One of the articles I read said that the round was based on the 8x57...did that article mean to say 7x57? In the Cartridges of the World book the round looked to be a necked up 7x57...the 8mm Mauser is a 30-06 size case as I recall.

If you compare the three rounds to each other, I think you'll find the 8x57 is a lot closer to the 7x57 than the '06. Sounds like you're looking at a very nice rifle.

quote:

Have you ever loaded .358 bullets in this caliber or did you have to custom order .356 bulets?

If .358 bullets were used or tried, was the cartridge able to chamber with the cartridge neck expanded .002 over what a it would have been with a .356 bullet.

Try this: Take a fired case from that rifle, and see if a .358" bullet will drop freely into the case thru the mouth. If the chamber in the rifle will allow the case to freely release .358" bullets on firing, you can use them with no bullet sizing, neck turning, or other gyrations! Then it's only a matter of working up the load, just as you would with any gun. Any slight sizing-down of the bullet to fit a tight bore (say, .358" to .354" or less) will be done as the bullet enters the rifling, and, since peak pressure with modern progressive rifle powders does not occur until the bullet has travelled at least 4"-5" down the bore, there will be no significant increase in peak pressure of a given load at all. BUT, the case neck MUST FREELY RELEASE THE BULLET! (This is why it is dangerous to use cases which have grown too long, or which have neck walls that are too thick.)

I once loaded ammo for a friend in TX who had two 9X57's. One was a drilling chambered for 9X57R. The other was a Mauser in 9X57. The drilling's 9mm barrel slugged .354", and the Mauser was .356". However, the necks of factory ammo fired in both guns expanded enough to let Speer 250-grain .358" bullets drop right into the cases. So we made ammo for the drilling with neck-expanded Norma 7X57R cases, and for the Mauser we used 8X57JS brass sized in the 9X57mm FL die and opened up to hold .358" bullets. We started out with mild charges of IMR 4895 and used Speer 220-grain flatnose bullets to work up deer loads for both of them. We kept the pressures down for the drilling ammo, since these rifles are nowhere near as strong as a Mauser!

If I had been looking for elk ammo, I'd have used the Speer 250 grainer, since this was back before Nosler was making .358" Partition bullets! Today, I'd use Noslers for heavy game in the 9X57mm.

I had no chambering or pressure problems when using .358" bullets in either the 9X57 or the 9X57R. I suspect that in German sporting arms, the chamber neck sections were made pretty "generous". At least, it was on these two rifles, and if you have a round you can fire, it is simple to tell if your rifle is made this way too. If you don't have a round to fire, a chamber cast will tell you what you need to know.

Good luck! The 9X57mm is a very good round!

RJM

The 9X57 is based on the 8X57, not the 7X57, and it is a simple matter to form them from 8X57 brass. I know some folks who have been able to shoot .358 bullets in their sporters, but as was mentioned I would slug the barrel and find out for sure what it really is. Both of the 9X57s I have had were built with .358 barrels so it wasn't a problem for me.

BTW, I sent you a P.M

Thanks to all of you that have responded with help...and I have "solved" the problem.

One of my long time best friends also is a .358 shooter. When I told him about the rifle he said he would buy it from me if I ever wanted to sell it. He missed out on three older sporters that were beat but would have bought any one of them just to have a 9x57...so it is now his. He knew all about the .356 vs. .358 bullet problems and where to get dies...so now I can shoot the gun any time I want without having to invest any money...

But again thank you for all your help.

Bob

quote:

Originally posted by RJM:
Thanks to all of you that have responded with help...and I have "solved" the problem.

One of my long time best friends also is a .358 shooter. When I told him about the rifle he said he would buy it from me if I ever wanted to sell it. He missed out on three older sporters that were beat but would have bought any one of them just to have a 9x57...so it is now his. He knew all about the .356 vs. .358 bullet problems and where to get dies...so now I can shoot the gun any time I want without having to invest any money...

But again thank you for all your help.

Bob

Bob, that's the best of all possible solutions!!