Making 257 roberts brass?

[Mauser48]

I have seen people talking about making 257 roberts brass from 6mm remington and 7x57 mauser brass. I cannot find brass anywhere for the gun. Is it better to neck up 6mm or neck down 7x57? Will i need to neck turn or fire form or anything? What is the best/easiest method of making 257 brass? Thanks!

[skeettx]

How many cases are you wanting to make??

Can be done that way, but why use expensive brass
I use 30-06 brass and use a 7mm trim die to form and using a jewlers hack shorten the case
Then into a 257 Roberts trim die.
Then Forster inside neck reamer and final trim
The chamfer inside and out
Then full length size and load.

If you live anywhere near Amarillo, Texas, we can make this happen

Mike

[frnkeore]

If you neck up the 6mm Rem cases, would be the easiest way to be sure that you don't have to turn necks. The 7mm case would be as almost as easy and has the same shoulder angle but, you'd have to make sure the neck doesn't thicken. I doubt that it would though. You'd also need to take care that you don't colapse a neck or case.

Really, I would just go with the best price and availability. Now, if your looking for the best brass, go with Norma 7mm brass. That is what I use in my 6mm Rem Imp. After reading up on the 6mm Imp in 1000 yard matches, that is what I bought because that is what they're using.

Frank

[Mauser48]

Thanks for the help im looking to make about 50 pieces. A guy at the gunshow sells 50 pieces of 7x57 for 25 bucks. I usually can get him down to 20.

[skeettx]

Well for that small number go with the 7mm Mauser brass.
Just use your regular dies and full length size them.
Load ONE cartridge and see if it will chamber, If so, load lots
If not, neck ream
Mike

[Mauser48]

How do you neck ream? And whats the difference between neck reaming and neck turning?

[RustyReel]

I used 7x57 brass when making my 257 Roberts and then shot some of those to form 257AI. Don't remember if I had to trim them after first reforming to 257, but if so it wasn't much....easy.

[WallyM3]

Turning is outside, reaming is inside. A reamer is like a straight fluted drill or end mill designed to take a small amount of metal off and produce a smooth, round surface...something a drill never can.

Which you do depends on where you need to get to dimensionally.

[seaboltm]

Its usually not hard to pick up 257 brass on gunbroker. look often as some people are asking ridiculous prices. I was patient and accumulated a couple of hundred pieces of once fired for about $75. That is enough to last me a very long time as I almost exclusively shoot 357/38 for range work and seldom shoot rifle cartridges.

[Mauser48]

Thanks for the help guys i appreciate it!

[dragon813gt]

How do you neck ream? And whats the difference between neck reaming and neck turning?

There is a lot of information if you punch either term into the search engine of your choice. You can get lost for hours investigating neck turning. Turning will give the necks uniform thickness to provide proper bullet tension. That's a quick summary.

[Mauser48]

When resizing the brass do i need to take the deccapping pin out on the first run through?

[gandydancer]

I may have some new stuff laying around. let me check and get back to you on weds. I have guests right now who never know when to go home. I am about to tell them. Tom

[Mauser48]

Thanks a lot tom i know exactly what your talkin about!

[skeettx]

See here

http://www.forsterproducts.com/catal...?prodid=700235

[Tackleberry41]

When resizing the brass do i need to take the deccapping pin out on the first run through?

I have made 8mm mauser from once fired 270 brass a friend gives me from a range he works at. I find it works better to size wout the expander inside, then go back and run them thru again with the expander in place. To much work for the press sizing and expanding at same time.

[UBER7MM]

I've made 8x57 from 30'06 and 7x57 from 270. Since the 30'06/270 cases are 1/4" longer than x57 you'll need to take the expander plug out of the x57 full length sizer so that the case will fit in all the way to the base. Then cut the brass down to size then size again with the expander plug in the full sizer.

I then neck turn the brass because it gets thickened during the reforming process. Neck reaming and neck turning perform the same function. Neck turning trues the outside of the case's neck walls. Neck reaming trues the inside of the neck walls. I believe that neck turning has less of a chance of off center alignment of the neck walls. Others may disagree. You'll need to invest in a neck turning or reaming tools to get the neck to the correct diameter and thickness.

I hope this helps,

[littlejack]

Just in case you are interested, there is 91 pcs of 257 Roberts brass for sale on the Swappin and Sellin site.
Jack

[skeettx]

http://castboolits.gunloads.com/show...rts-Brass-91pc

[Mauser48]

What is the best brand brass to use in terms of case capacity? Does it matter if the brass is mixed head stamp?