8mm Mauser

[polaris]

forming 8mm Mauser brass from 7mm Mauser brass, what are your thoughts?
will the necks be too thin?

 

[Longwalker]

forming 8mm Mauser brass from 7mm Mauser brass, what are your thoughts?
will the necks be too thin?

I've formed .35 whelen from 30-06, and my brother makes .358 win from .308. If the necks are too thin there is no indication of that, our cases work well.

Lube the inside of the neck, use a tapered expander, and Voila! Your new 8x57 cases may have slightly short necks, which doesn't really matter anyway. Remove the lube before loading.
You might lose a couple cases to neck splits. If that seems to be a problem just anneal the 7mm case necks first.

 

[tiriaq]

I've made 8mm Mauser from .30-06. FL size, trim. '06 is easier to find than 7mm.

 

[Eagleye]

Biggest problem making 8x57 from 7x57 is the shoulder. The distance from the head of the case to the shoulder is shorter on the 7x57. If you expand the neck of this case to 8mm, you will end up with massive headspace issues. Dangerous, to say the least. Use 30-06 brass, it is good for that job. Better yet, buy some 8x57 brass, it is not exactly hard to find. Eagleye.

 

[polaris]

thanks guys for all the good advice.

I think I will use 30-06 brass (have quite a few hanging around)

 

[Tex Critter]

Rgr on the .30-06 brass. I reformed a couple hundred cases to 8mm and they are excellent. Then a friend gave me a hockey sock full of Remington 8mm brass. Now I is a very happy camper!