Ladies and Gentlemen:

I have a 1909 Argentine that I would like to make into a classic peep sighted Africa rifle. I have noticed that my 8x57 Winchester brass is getting pretty small at the head about .465". So it is a sloppy fit with the original extractor.

Does anyone know if the Norma 8x57 brass has a larger diameter head, nearer to .471" or more?

My .471" diameter .243 Lapua brass is held nicely by the same bolt and extractor.

Thank you.

Sincerely,

Chris Bemis

I think what you have there is Winchester is fudging by using 30-06 brass as the base for their 8x57 cases and Lapua is using ??x57 brass as the base for their .243 stuff. So if Norma follows the same idea, their brass should be of a proper size.
I don't know for sure.

I have a couple of old boxes of unfired Norma 8X57JS brass ($2.60 stamped on the boxes should tell you how old they are). Miked a couple and the head diameters look to be .4665". Might be the extractor groove diameters that are smaller. These measure right around .400" as best as I can tell. Hope that helps. Paul.

My old Lyman manual shows 0.473" for both '06/.308 and Mauser (8x57) brass. My Winchester '06 brass measures 0.465", and LC measures 0.469".

At what point does any of this constitute a problem? I've never thought of a Mauser-style extractor being overly sensitive, and the original design being least so. A military gun doesn't require close tolerances to function properly.

Is the extractor an '09 Argentine (7.65x53) extractor? If so, I suggest trying an extractor from another M98 that is chambered for the 8x57. I've been through this before. Some say that all M98 extractors are the same. I had the sloppy fit on an '09 that I built in 257 Roberts. Replaced the extractor with a NOS Argentine extractor and still had the same slop. I then tried an extractor from a VZ24. Problem solved. I do believe there is a slight difference in the extractors.

The 7.65 Mauser has a slightly larger head than the 8X57 so the 8X57 is by design looser.
The .243 works better because the rim is thicker.

quote:

Originally posted by SR4759:
The 7.65 Mauser has a slightly larger head than the 8X57 so the 8X57 is by design looser.
The .243 works better because the rim is thicker.

Yup, .473" for the 7.65 and .470" for the 8.

quote:

Originally posted by craigster:
Some say that all M98 extractors are the same. .... I do believe there is a slight difference in the extractors.

Only the stupid ones say that. You are right, there are differences.

quote:

Originally posted by z1r:

quote:

Originally posted by craigster:
Some say that all M98 extractors are the same. .... I do believe there is a slight difference in the extractors.

Only the stupid ones say that. You are right, there are differences.

Yeah, they're out there, all right. I gave up trying to fix stupid quite some time ago.

As posted, we're not working to that tight of tolerances in milsup rifles in the first place and .006 ain't a whole lot.
That how domestic companies can get away with using .465 (30-06) sized brass and european companies can use .471 (8x57) sized brass for the same cartridges.

Dear VIP:

Thanks for the miked head measurement on your Norma 8x57 brass.

Gentlemen:

Thank you for your input.

Yes, I know the 7.56 Argentine case head is a bit larger in diameter, and the 1909's are a bit sloppy with standard 8x57 brass, so I am taking that into account.

It's just that some old 1970's 243 Winchester brass that I have laying around runs out at .468-.469" and it fits correctly, too, with the original 1909 Argentine extractor. I don't want to swap out the extractor, since the whole action is cherry, and everything fits just right.

I would prefer to get some larger head diameter 8x57 brass, but I don't think that is possible. Norma was my last chance.

I probably will have to have the extractor end TIG'd a bit to give me a better bite.

For your information, I have found the K98k extractors to be very tight even on the .465" 8x57 brass. I like the rounded bottoms on the front part of the K98k extractor, which I copied on an opened up 1908 Brazilian extractor (that had a squared off bottom) for a 375 Ruger.

Sincerely,

Chris Bemis