6mm AI from 7x57 Brass

[DJ]

I am new to this site and it is full of great info!!
I am looking for some info on forming 6mm brass from 7x57 Norma brass. Everything I have read says this is the best way to go, and everyone seems to have their own method. I have a Redding full length sizer in 6.5-284 win & 6mmAI and a 6mm rem Lee collet neck sizer. I removed the expander from the 6.5-284 die, lubed the neck and ran it thru...re-lubed the neck and ran it thru the 6mmAI die. The whole operation felt smooth until I got to the expander on the 6mmAI die and I was met with a great deal of resistance. The resulting case had a rounded shoulder and the mouth of the case was visibly high on one side and I had to trim the cases to 2.223 just to square the case mouths. IS THIS NORMAL???? I also tried it once without the 6mmAI expander and the result was a neck that was too tight and could not be put back thru a 6mm die. I am waiting on the barrel, so I can't chamber a round to see how it feels.

Thanks
DJ

 

[RDavies]

I used Norma 7x57 brass to make my 22-6mm IMP which is a necked down and fireformed 6mm Rem. I used a std 6mm Rem sizer to neck it down from 7mm. Not a sizer with a neck bush, just a std type one.

 

[DJ]

Thanks for the reply. Did you experience the rounded shoulder after you sized them? It just feels like the expander in my 6mm die is actually pulling the shoulder out. Hopefully this will end up positive and help with the tight fit for fireforming.

Thanks again
DJ

 

[Preacher]

Not much support on the case with a 284 die, and pulling down .041 in one pass is not a good idea. A improved die won't allow a good support either..
A 257 Roberts FL die is a good choice for a intermediate sizing... then right to a 6mm FL die...
Your moving a lot of brass, and it needs neck turned I imagine before it will be safe...

 

[DJ]

Thanks Preacher.......on the neck turning note. It's been said you need to cut into the neck to avoid a donut. I have already turned the neck with a K&M turner to allow .003 clearance, but did not cut into the necks because I did not know if it was a good idea before fireforming,I'm new to the whole AI and reforming brass thing). Any thoughts??
Thanks again
DJ

 

[DJ]

Correcton to my last comment.......I meant to say 'cut into the shoulder'

 

[Preacher]

I knew you didn't mean that
You need to cut into the shoulder so it seems to blend in with the whole case, not a lot, but enough to see for sure that your into the shoulder. I always turn my cases before I do any necking down..
Heres a photo of 2 cases, the top new one is cut into the shoulder just right, and the bottom one was just fired.... I hope it helps you a little.....

 

[DJ]

Nice pics...you rock! Thanks again for the help. My 6mm rem and 257 roberts FL dies are on their way.

DJ

 

[fly18s]

I know this is an old thread but why go to all this trouble and buy more dies when you can just buy 6 mm Remington brass and run it thru a sizer ( .240 PSP ) , then fire form .240 PSP or .243 AI brass ?
I’ve just started reloading for a .240 PSP, 24’ barrel sporter weight rifle on a 98 Mauser rifle.
I asked a gunsmith why no one see seems to be loading the PSP and he said all those people are
Dead. .
Those 243 and 6 mm wildcats are still good calibers
Thanks.