Will a rifle chambered for 8X57IS rechamber to 8X64 Brenneke without setting the barrel back? Since the 8X64 is essentially the 8mm-'06, which was developed with the thought of rechambering 8X57 Mauser bring backs from World War II to a cartridge using easily available brass, I would assume that to be the case.

Unlike the 7X64 Brenneke, the case head on the 8X64 is virtually identical with the .30-'06 case head, so brass can be formed from .30-'06 (slightly short) or .270 cases.

Measure the shoulder OD on an 8x57. then measure the OD of the 64 case, at the same point. If the 64 OD is the same, or ideally larger, then yes. If not, then no. Or you would have a little extra shoulder there which wouldn't hurt anything; just look funny.

According to my calculations, the 8X64 chamber would measure 10.96mm at the same point that the 8X57 would measure 10.95mm, but what I am interested in is whether anyone has experience in actually rechambering an 8X57 to 8X64 or 8mm-'06, and if so, how the operation turned out.

Been there , done it.
Body and shoulder make no problems. There is only a slight difference in the neck diameter. The
8x57 IS is slightly wider. So you have a little marking on the fired cartridge. Better yet is to bring the neck diameter of the 8x64 S chamber to the 8x57IS measurements.Tat was made for me by Fuhrmann Jena. Triebel Tooling has special reamers for that action.
For me that worked fine without any loss of precision.

quote:

Originally posted by xausa:
According to my calculations, the 8X64 chamber would measure 10.96mm at the same point that the 8X57 would measure 10.95mm, but what I am interested in is whether anyone has experience in actually rechambering an 8X57 to 8X64 or 8mm-'06, and if so, how the operation turned out.

8x06 -- works fine -- i've done a couple, had a few more ... basically zero issues other then 1 must have had an oversized 8x57 reamer or it was wobbled, as the fired brass was slightly wonky -- nothing a resize didn't fix ..

The re-chamber job can be done but the base diam of the 8x57 case is listed as .470 " while the base diam of the 8x64 is listed as .464 ". The 8x64 will certainly expand that .006" when fired but is that going to overwork the brass when sizing those cases ?

The brass does not give a jot about hat mini difference.

The Wikipedia article on the 8X64 Brenneke indicates a .470 base diameter. The 7X64 has a smaller base diameter.

I found the .464" measurement in the Cartridges of the World specs. One of them is likely a misprint. The CIP specs would likely show the correct dimension.

I'm late to the thread. But as well as the excelent 8mm-06 there is another choice. The 8x60S. This was a post-WWI cartridge developed to allow civilian possession of prohibited military calibre 8x57S rifles.

It is 2mm longer on the body and 1mm longer on the neck. So deliberately designed to take out the 8x57S shoulder. It is no more nor less than that. The rest of it is identical to the 8x57S. It was done by simply putting a chamber reamer into an 8x57S. That's all. Shoulder forward 2mm...neck extended 1mm that's all.

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However the problem Americans have had with both 7x57 and 8x57 is your poor powders and an obsession with 1888 Commission Rifles.The 8x57S is/was seriously underloaded in the USA and this is also because US powders were poor compared to contemporary German powders.

Now that the US has excellent double base powders the 8x57S finally has got good American powders to realise its original potential. I'd try these powders and you may decide that you don't need to change. For WITH DOUBLE BASE POWDER the 8x57S equals if not exceeds the .30-06 in most equivalent bullet weight loads.

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There's no need IMHO to take it out to 8x64. And, if I were to go that route I'd go 8mm-06 in any case. A American 8mm classic cartridge...it's a fine connversion. 8mm-06 is a winner! And 8x60S too. 8x64? I don't think it offers any advantage now modern double base powders are arrived.

I have owned both 8x57S and 8x60S. 8x60S is a step up from 8x57S and, yes, the brass can be made from merely running .30-06 through an 8x60s die and trimming it. PRVI Partizan also make 8x60S brass...RWS once did but don't.

Interesting comments on the 8X60. However, I already have two Oberndorf sporters, one marked 8X60 Normal and the other 8X60 Magnum, plus a drilling with an 8X60R rifle barrel. I killed two deer earlier this season with my Sauer & Sohn transition model Mauser 8X57I, so I have no doubts about its capabilities, but the particular rifle I am considering modifying is a BRNO 21 which has been already extensively modified, and I would like to take advantage of its full length magazine and add a little potential performance to its 20" barrel. http://www.egun.de/market/item.php?id=6758377.

Hmm. I'd last see if there is a usuable difference in case capacity between the 8x60S, 8mm-06 and 8x64.

My own gut feeling is that when bullet seating depth is taken into account there may not be much real world difference.

But it does seem an interesting project and I've always thought .323" a good calibre.

My liking has always been for the 196/200 grain bullets...Speer's in particular.