.257 Roberts brass vs .257 Roberts +P brass

[3S16]

I'm having a really difficult time finding brass to reload for my .257 Roberts. None of the usual internet sites seem to have any.
I have found some new Nosler .257 Roberts +P brass.
I'm guessing the +P cases is a little thicker in places, but Is there any reason I can't reload to normal .257 Roberts specs and will it chamber in a in a normal rifle chamber?
(I shoot a 40 year old, post-64, Winchester 70 Featherweight in .257 Roberts.)

[rockquarry]

If there is a difference it would likely be a small one. I'd bet it's the same brass as non+P only with the the different headstamp. There's always going to be small lot-to-lot differences (weight) with each batch of brass as well, but usually not enough to matter. If you have a real concern about this, call Nosler.

[diyj98]

Thanks m betting it’s just a headstamp.

[3S16]

Thanks for the responses. I think you're right. Probably just the headstamp. I'll call Nosler in the morning.

[Igiveup]

I shoot .257 Roberts, but I reload, so the brass doesn't much matter for the same load, which usually is a +P equivalent load. If the brass says +P, you don't have to reload +P.

[Cdog]

Headstamp. My experience has been it's the same brass.

"Bob" is the first rifle caliber I loaded. Still have an A-Bolt chambered in it.

I remember when we used to use plentiful 7X57 brass for the .257. Last time I searched for 7X57 brass for my Winchester I ended up necking up .257 Roberts brass I had on hand.

When I did locate 7X57 brass I bought several bags. I still have some of the .257 that I necked up years ago. The 6mm Remington was a victim of terrible marketing. Mid length calibers that are mostly overlooked today.

If you dead end on your source and need some new Remington or Winchester brass. I'm almost sure I have enough to share some of them with you.

I just did a quick search, and whew! They think a lot of Nosler brass!

Just my two cents. It appears 7X57 brass is fairly plentiful now. Before I spent $2 apiece on the Nosler, I'd buy and neck down the 7X57 brass.

Prvi Partizian Unprimed Brass 7mm Mauser (7x57) (50) - Powder Valley

[zeke]

Have read that Winchester's plus p brass was made stronger than the older brass to take the newer slightly higher pressures the 257 roberts was being loaded to. However this was from years ago, and do not know how relevant now a days. While there are certainly situations of plus p brass just being a modified headstamp like 38 special, there are instances of the brass being modified for higher pressures (starline's 45 acp versions).

[zeke]

https://www.grafs.com/retail/catalog...ategoryId/681?
Shop Rifle & Shotgun Reloading Supplies | Dies | Bullets | Hulls | Wads | Powder - Precision Reloading

very spendy, but noslers version available.

[DWalt]

This is the first time I have heard of .257 R +P. Is that even something SAAMI recognizes? I guess I don’t understand the need. Back when I had a .257, I do not remember using any factory ammo or brass, I just resized 7x57 or 8x57 brass in a .257 FL die. I still have the .257 die set.

[stan v]

Originally Posted by 3S16

I'm having a really difficult time finding brass to reload for my .257 Roberts. None of the usual internet sites seem to have any.
I have found some new Nosler .257 Roberts +P brass.
I'm guessing the +P cases is a little thicker in places, but Is there any reason I can't reload to normal .257 Roberts specs and will it chamber in a in a normal rifle chamber?
(I shoot a 40 year old, post-64, Winchester 70 Featherweight in .257 Roberts.)

Heck, I reload +P in reg 257 Roberts brass.

[murphydog]

I would be curious to know if case capacity between the regular and + P versions is significantly different. If the latter has thicker case walls the internal volume may be less than the standard case, but maybe not to the point where the powder charge is limited.

[zeke]

from yr 2000 hdy 5th edition "Some cases currently designed for +P pressures in the 257 Roberts, and have sligtly less powder capacity. Segregate your brass by brand and develop your loads accordingly"

The cases listed as being used by them are not specified as being plus p (Hornady/Frontier).

Remembering the 257 Roberts went commercial in 1934, and reportedly at a lower pressure than more modern rounds.

[DWalt]

I doubt that any rifles that were factory chambered for the .257 R had weak actions, and assuming correct head spacing, I can see no reason whatsoever for having a +P load. Can anyone explain why a +P case would provide any additional level of safety of safety over a standard .257 case?

[GB]

Like everyone has stated, you are good to go with the +p brass. With the rifle you own you can shoot any reasonable load. I could go on for hours about the attributes of the 257 Robert's. It was the first rifle I bought when I moved to WY and has accounted for most of the speed goats and all of the deer I have harvested since moving here 40+ years ago I also like your Featherweight, I have that rifle in another old time cartridge, 6.5 X 55. Anyway, back to the Bob. With care you can get many reloads from your Nosler brass and a hundred will last most of a life time. Babble over.

[old tanker]

Weigh the brass. If the +P headstamp is consistently and significantly heavier it probably has less volume. Whether or not it is enough to matter depends on if you sort your brass or not anyway.

[zeke]

Originally Posted by DWalt

I doubt that any rifles that were factory chambered for the .257 R had weak actions, and assuming correct head spacing, I can see no reason whatsoever for having a +P load. Can anyone explain why a +P case would provide any additional level of safety of safety over a standard .257 case?

Sometimes ya can just google it

.257 Roberts: created during the 1920s, this classic short-action cartridge was, according to the author, the original varmint/deer combination cartridge. - Free Online Library

[rockquarry]

Originally Posted by DWalt

I doubt that any rifles that were factory chambered for the .257 R had weak actions, and assuming correct head spacing, I can see no reason whatsoever for having a +P load. Can anyone explain why a +P case would provide any additional level of safety of safety over a standard .257 case?

There may be a little more to the story than what I remember, but... when the .257 +P factory loaded ammo came about thirty-five or so years ago, I don't recall there being any inference that the brass was stronger, only that the ammo was loaded a little hotter than it had been for decades. I don't know why the .257 Roberts had been downloaded for so long.

[Cdog]

I’ve been loading .257 for more than 35 years. I’ve never seen any difference in +P stamped and standard.257 brass. Loaded all of it at the 58K levels. Same with 7X57. More often than not RP brass is heavier than Winchester. Federal is usually the heaviest.

The older rifles limited pressures, not the brass.

My preference runs toward the Winchester brass.

[3S16]

I spoke to a Nosler reloading tech via their Customer service line today. "Standard" .257 Bob brass is rated at a pressure of 54,000, The +P is rated at 58,000. The slightly thicker brass is a "Liability" thing. No problem using +P in any reasonable loading.
Thanks for all the great info. I too have been loading the "Bob" for 40 years. My first real deer rifle - still my favorite, now with a 100 gr Barnes TTSX.

[DWalt]

SAAMI does have chamber pressure specs for both .257 R and .257 R +P. Maximum Average Pressures are 54000 psi and 58000 psi respectively (piezo gauge method).

[Ivan the Butcher]

In the late 80's I was in a shop in Columbus that had a used 257 rifle. There was a number "4" just in front of the action. The shop owner said look at this, and handed me a piece of paper. I had a 4 at the top of the page, and was titled "Loading Data" at the bottom was a simple signature...NED

That gun had belonged to Harvy Donaldson, the shop belonged to Harvy's cousin.

Ivan

[zeke]

Remembering that thicker/heavier does not automatically mean it is stronger/less capacity. Although imo, heavier usually equates to less capacity. Winchester cases are very noticeably lighter than most brands of 308, especially Rem and Fed. Am betting this holds for several calibers. Don't know if i have any older cases left to compare to the Win plus p am currently using. Am liking the Browning micro (i think it is a micro) in 257 roberts that has a leade that fits a longer col if the magazine is modified. Although it might be a largely academic discussion in this day and age.

[ArchAngelCD]

You might try calling or emailing the manufacturer of the brass and ask them first. Failing that you can do some tests for yourself.

I'm confused. Why so much debate without just testing the brass? IMO weight is not a good method of deciding if it's stronger or not. You probably have to cut a few cases apart and measure the thickness of the case walls. Then you will need to check the capacity of the cases. (with water like the pros lol) Then you need to check the hardness of both type of case material although I have no idea how to do that. Maybe the tools used to check lead hardness might work.

Discussing it on a forum is fun but unless someone here has already spoken to the company or done tests to verify if there's a difference, it's all just speculation.

If you do without a doubt find out please inform us of the results.

[2152hq]

Don't get hung up on +p headstamp marks.
Brass cases are all different from different sources & lots. They'd be different if you made them from commercial '06 and then again surplus '06. Diff again making them from 7x57 or 8mm commercial or surplus.

So many variables...
It is all wiped away when you follow a basic rule of reloading.
Start at the minimum load and work up.
Watch for signs of excess pressure.
Do not exceed Max load data.

Pretty easy really.
The '+P' mark on the headstamp is no license to run the loads to extreme and not accept that absolutely nothing can go wrong.

So one is rated 54K and the +P is rated 58K
Such a big difference,, I'm impressed,,not.

I wouldn't load to either extreme anyway. No need to.
But then that's just me.