Krag Collectors Association Forum

Hi;
due to a shortage of 30-40 brass, is it technically possible to reform a functional 30-40 case from 7X57R brass?
I know, It would be better with 303 but a friend gave me a big package of 7X57R.
Regards

Possible but impractical for average home workshop. Problem is base diameter. 7x57R is about .015" fatter at solid web region than .30/40. That much reduction takes special dies and heavy-duty press - or turn down on lathe and risk over-thinning at web-wall junction.

Powder Valley has Winchester 30-40 brass for $27.50 for 50. Beats all that work converting.

Parashooter wrote: ↑Sun Mar 21, 2021 9:11 pm Possible but impractical for average home workshop. Problem is base diameter. 7x57R is about .015" fatter at solid web region than .30/40. That much reduction takes special dies and heavy-duty press - or turn down on lathe and risk over-thinning at web-wall junction.

Parashooter,
If the OP were to reform them that much smaller, would the case capacity be reduced enough to cause over pressure with standard loads? Reloading manuals used to always have warnings to reduce charges 5% when using GI brass for 06, starting with unknown case thickness and reducing it might cause even more headaches.
Seems like selling them or giving them away and getting 30/40 brass is a better plan, someone out there may be turning the word upside down looking for that 7X57R brass anyway.

The rim would keep you from swaging the base small enough. I used to make 6.5 Japanese by swaging down GI 7.62x51. Even with the base being fairly far forward because of the extractor groove design of the 7.62, .4575" was as small as I could swage the base without also reducing the rim. You might be able to turn them, risky business. Thanks to GI bring backs, there are still quite a few 7x57R rifles around, sell it to someone.

The OP, 'donki1967', lives in France.
Some of the suggested sources for .30-40 Brass and possible swaps, may not work for him.

Thank you for your contributions, I will wait wisely for 30-40 brass availability.
Regards from France

Maybe the 6.5x53R Dutch and Romanian, which can be made from .303. Brits called the little rimmed case the .256 Mannlicher. The British 240 Magnum Flanged could be worked down and fireformed.