9.3x57 from 30/06

[Huvius]

First thing i do is anneal the neck and shoulder of the case.
I expand the necks of 25/06, 280 rem, 30/06, and 270 to 0.415" or so...

This is an important step as you not only want to your neck size correct but your shoulder set correctly.
I learned this making 9.5x57 (375 Express) from 30’06 as simply opening up an 8mm or 9.3 Mauser would make cases that chamber easily but would have excessive head space.
Making a new shoulder and adjusting the die to achieve a firm bolt closure is the best way to avoid this.

[lar45]

I've worked with 2 different models of 9.3x57 and both had excessive headspace, long throats, and a large groove diameter.

If you are making cases out of longer 30-06 brass, then I would suggest leaving the sizing die turned out abit until you get your formed cases close, then turn it in a little at a time until the bolt handle closes tightly on the brass. Then fireform and reload the longer cases as normal.
If you are necking up 8x57 brass, I'd suggest necking it up to .375 or .416 first, then neck it back down with the same process to create a shoulder in the proper position.
I have read about several people who get short case life with case head seperation because they full length size the cases everytime.

The throats are over .5" long and about .370".
The two models have different barrels, one has a 4 groove, and the other a 6 groove.
I have a folder with lots of notes and measurements from chamber casts, with targets and load data... But I can not find it anywhere.
If my memory serves me right, one of the barrels had a groove of .368 and the other .369.

Someone here sent me some bullets cast from an NOE mold. I didn't spend much time with them, but they shot great.


I tried the Speer 9.3 270s with CFE223. They shot pretty good, but didn't give the velocity I was looking for.


To fit the oversize barrel, I ended up using Speer .375" 235s and sized them down to .369" in an NOE sizer with lots of Imperial sizing die wax. Loaded with H4895, I got them up to 2500ish and took a Deer with them. The bullet penetrated stem to stern and kept on going.



I made some cases out of Rem 30-06 brass just to try it. I necked up in a few different steps, then set the shoulder back to get a tight bolt closure, cut the neck. Then I necked it up to .375 and outside turned the necks(I already had the .375" tools), then necked back down to 9.3 and trimmed to length. I annealed after all of the up and down sizing.
They worked great for cast bullet loads. I didn't try them with jacketed.
I read somewhere that the chambers were a little sloppy and turning the necks to get rid of the doughnut wasn't necessary. I already had all of mine turned, so I didn't try it.

FWIW

[Landy88]

These old Husqvarnas seem to be each an entity unto itself. My M46 head-spaced correctly with 8x57s simply resized in 9.3x57 dies.

I got off easy with just measuring it first, but these are definitely measure first rifles. I think that the rifles and cartridge are fine enough to be worth the effort.

[Tedly]

I've made 9.5x57 Mannlicher Schoenauer out of 30-06 , home made expander after anneal , lots ot trimming after . Usually done in a Bridgeport