Anyone done a 357 mag necked down to 6mm/243 for a Martini ?

Roger

Kinda like a 256 Winchester.

I reloaded the 256 Winchester and sizing 357 brass resulted in a lot of cracked/deformed cases. Nickel cases in particular.

one of my cadets is 256 it is a fun plinker

Matt,
What I do is, I use once fired .357M BRASS

#1 Full length size in .357M carbide die

#2 ANNEAL neck and shoulder area

#3 Lube cases with Imperial Sizing Die Wax (Also sold by Hornady and Redding I believe)

#4 Full length size in .256 WM full length die by BUMPING a little at a time until fully sized A few of the cases may come out with a few wrinkles in the neck/shoulder area but they seem to last just as long as the unwrinkled ones.

This seems to work with nickel plated cases but you are right, they don't last as long.

The sizing die wax and the bumping seems to be the trick.

Hip

Now back to the 6mm/.357!

I remember a G&A story about woodchuck hunting on a golf course. The writer has a short carbine Martini in a gold painted mannlicher thumbhole stock in that caliber.

...actually that was a 44 mag necked down to 17...close but no cigar

Roger

I did one on a 357 maximum case. I ended up trading it for something, dont remember what. The guy used it for his kids first deer rifle.

Was that in a Martini Cadet?

Roger

I had G&A and AR from 1960 to about 2004.

Had to throw them out. Wish I had a bulk scanner.

Yes Roger, that was a cadet.
I have a cadet in 357 Maximum, had to deepen the loading trough to get shells in and out. With the neck and shoulder of the 6mm, no problems.

What did you use to neck the 357 down to 243?

Roger

Had a customer with one.
Neck up 22 Jet and fire form

M

I used a set of 300 black-out form dies, but that was for 357 max brass.
Yes, fireforming jet brass with be the simplest way.

Maybe so, but down here jet brass is unobtainium, I have bags of 357 brass...

Roger

I have a 256 Win. A 30 Mauser or 30 Luger die works great to neck down the 357 case and form a shoulder. From this I run them into the 256 die. Never have any failures this way.

Thanks for the tip, then maybe a cut down 243 Win. die to get to 6mm.

Roger

This one ?



Roger

I can't believe you have that. I threw out my G&A. Had from 1960 to 1995.