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/catalog.asp?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/showthread.php?248178-257-ROBT-Roberts-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?

[skeettx]

Not too much, you most likely do not have a benchrest 257 Roberts
Mine is an old Remington 722.
For serious hunting I would make up one box of like headstamps and load
it perfectly (scale) to know if I miss, it is MY FAULT :)
Mike

[frnkeore]

Does it matter if the brass is mixed head stamp?

Yes, it can matter a lot. Case capacity, head thickness, wall thinkness and case hardest need to be the same from shot to shot.

As I posted before, the 7mm Norma brass will be the most consistent and last the longest. After that, I'd choose Winchester.

Frank

[MauserFan98]

I use PPU 7x57 brass and resize before first firing, after that neck size only. Works like a charm with minimal trimming. I shoot a custom M93 rebarelled to 257. Excellent accuracy and great on Texas and Arkansas white tail and hogs. Going to try my hand at varmints next

[Texas by God]

Since Privi now makes 6mm Remington brass, I would buy it and neck it up to the Roberts. Excellent affordable brass IME.

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[clearwater]

I make 7mm Mauser Improved brass from 06 and 270 brass. Run it thru the die, then use a mini pipe cutter to shorten it before I trim it with a lee trim set up. Fire forming is needed to get the full Ackley size.

Wonder if you could do the same with 25-06 brass to get Roberts, sans the fire forming?

Reaming can be a pain, so if it were me and I could get 6mm. that is what I would do.

[flounderman]

any time you are sizing the neck down to a smaller caliber, you end up with a thicker neck and it can raise pressures. If the neck holds a bullet after you fire form it, it needs to be reamed. This also can be from the neck being too long. I would try to find used .257 brass, places like American Reloading have new brass they have pulled the bullets from and you can buy new, primed brass cheap. If you size longer cases to 257, you probably will have to anneal and ream. Not sure the differences in 6mm, and 257, but if you are buying 6mm brass, you just as well buy 257

[MostlyLeverGuns]

Neck reaming follows the easiest path and CAN lead to off-center necks if the case and reamer are not held true. RCBS makes a neck reamer die and cutter that hold tolerance. Neck turning provides a uniform neck wall thickness. Plenty of info on both on the long-range and precision shooting sites. A standard factory chamber will 'PROBABLY' take the necked-down 7X57 without problem. Sometimes a thicker neck on a case can improve accuracy.

[Texas by God]

Necking up the brass avoids all the silliness of reaming or turning. I have made 7 - 08 from .243, .358 from .308, and .250 Savage from 22 - 250 with no problems and no reaming and no turning. I mentioned the 6mm Privi brass because it is available now and 257 Roberts does not seem to be.

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[clearwater]

I make 25-284 brass from 284. Similar sizing amounts, 7mm into 25 cal. I neck turn just because I have the gear and to hopefully increase accuracy, but the turning rarely takes off very much and isn't needed to fit the chamber. Same with my 25-270 that I make brass for from 270 and 30-06. I use nail polish in the base stamping to help distinguish the brass from the original caliber.

[waco]

Kinda pricey but I just bought a new box of Nosler 257 Bob brass.

[Mr_Sheesh]

ammoseek and (sadly not so usable here) gunbot sometimes can help;

257 loaded rounds (hope you like 117 Gr bullets) for $1.34 {Hornady} - $1.45 {R-P} - I prefer 100 Gr. in Jacketed bullets but as my old R-P brass was getting old, got my good old woods partner new brass. Probably will go back to 100 Gr. bullets and change the scope to a better one & the mount to a non tip off one; Weaver K4 is a decent scope but my eyes are not as good as they were when I was 14 LOL

I could have reformed brass but already have 1000+ to form in other calibers, us old guys have to conserve energy some times :)

[Lloyd Smale]

ive done it both ways. Ive never had a need to turn necks after using 757 and if using 6mm I make sure to lube the inside of the case neck. No need to remove the pin. Just run them through the 257 sizing die check the length to see if they need to be trimmed and if not just load them.

[MauserFan98]

I’ll try that. Thanks!

[Texas by God]

Mauser 48 I sent you a PM.
Thomas