I made 6mmRem from 270Win, but....

[LR338nut]

So, before anyone asks why, because I was bored and cant find any 6mmRem or 257Roberts anywhere.

I annealed the 270's, lubed them with imperial wax, pulled the expanding stems from the dies, stepped the necks down to 6.5mm then down to 6mm. Once I had the cases formed to 6mmRem the necks were expanded then trimmed to length. I was also going to turn the necks, might have to ream them too.

The problem is that where the shoulder meets the neck the case developed little vertical creases in the brass. I annealed the next case further down the case body and the creases came out worse.

The creases don't look like they are bad enough to be unsafe, however they also don't look like they will fire form out either.

Does anyone have any suggestions on how to do this without getting creases in the case shoulders?

Thanks in advance.

 

[flashhole]

Try one w/o annealing and w/o the intermediate sizing step. Just do it all at once and see what you get. What headstamp brass is it?

 

[Rustybroadhead]

A while back, I was looking really hard at doing a 6mm build on a long action and decided against it due to a lack of brass but......

I have since found some. It is not always available but if you keep looking, it does pop up and sometimes in a good quantity (500 or more)

Go to the reloading section of gun broker. When someone lists a full bag, contact them and ask if they have more. I found one guy that had 7 bags of winchester.....

Good luck

 

[Rustybroadhead]

Here is one

6MM Remington New Brass by Winchester : Reloading Supplies at GunBroker.com

I do realize this is not nearly as much fun as making your own..... Good luck

 

[mrbig]

7x57 will work also if you can find it

 

[LR338nut]

I know that I can use other brass to neck down but right now Im more interested in making it out of what I have, which is 270 and 30-06.
I tried to neck it down in just the 6mm die and I crushed the shoulders, and I was using Rem and Fed brass.

I will try it again with a non-annealed case. Why would that make any difference?

 

[mrspradlin]

Let me know what you come up with.
I have a tight neck 6mm remmington imp. Been using Norma 7X57 brass

 

[Khavic]

I get the little dimple/crease every now and then making 7-08 out of 308. I have experimented a little and found it does fire form out. I use some light 110gr HP's and a light load of RL17. The brass forms every time and of the nearly 100 brass I've done this with, none have ever cracked or had case neck separation.

Hope that helps. Good luck.

 

[flashhole]

I reform a lot of 30-06 to 25-06. I especially like the "Greek" brass with the HXP headstamp for reforms. This link shows what I do albeit I used 270 brass when I storylined the process. I tried it with and without annealing and migrated away from annealing the HXP brass. I also reform a lot of 223 to 221 Fireball. That's a lot more involved and there I prefer military brass and I do anneal. That is shown in the second link. It's rare that I get a reject or wrinkled piece.


Resizing Brass - Shooters Forum

I finally got around to it - 223 to 221 Fireball (pic heavy) - Shooters Forum

 

[LR338nut]

Update.
I tried necking them down with out annealing, and with out an intermediate die, and it resulted in badly creased and folded brass in the shoulders and necks.
Annealed and necked down with just the 6mm die resulted in creased necks and shoulders.

Best so far: Annealed, necked down in a 260rem die with a O-ring spacer (so I don't bump the shoulder back too far), then necked down in the 6mmRem die, trimmed, and neck turned. This has eliminated the creases in the cases for the most part.

 

[flashhole]

Write it all down so you don't forget the steps. Glad you figured it out.

 

[stranded]

LR338nut, I was just reading this and wondered about the neck turning. Good find. Seems like the folk over at 6mmbr do a lot of wildcatting and I thought I remembered neck turning was important. The O-ring spacer is good too.

 

[LR338nut]

LR338nut, I was just reading this and wondered about the neck turning. Good find. Seems like the folk over at 6mmbr do a lot of wildcatting and I thought I remembered neck turning was important. The O-ring spacer is good too.

I use garden hose flat O-rings to "float" all of my dies to reduce run-out. I simply doubled up the O-rings to keep from bumping the shoulder too far when sizing in the 260 die.

But the necks are too thick to chamber with a bullet seated so they need to be turned down a bit.

 

[woostri]

Let me know what you come up with.
I have a tight neck 6mm remmington imp. Been using Norma 7X57 brass

Ditto. That's my method for 6mmAI. What bullets do you push? I use 115 DTACs at 3100 fps. Good stuff.