Which 257 Bob brass for the AI?

[long40shot]

Does it make any difference if you use regular or the +P brass for 257 Roberts Ackley Improved cases?

Thanks,
Matt

 

[Barlow]

I have used regular old Remington and Winchester for years with no issues. Barlow

 

[centershot]

The latest Hornady manual specifically says that their loads were worked up with +P brass. So there must be a difference.

 

[jepp2]

The latest Hornady manual specifically says that their loads were worked up with +P brass. So there must be a difference.

There is. The water capacity of the Winchester +P case is 57.8 gr. and for regular Winchester brass is 59.2 gr.

 

[oldduc]

Does it make any difference if you use regular or the +P brass for 257 Roberts Ackley Improved cases?

Thanks,
Matt

Nowadays, you just about have to use what you can find (or afford) I've been using some Nosler +P that I found in a LGS s couple years ago, but used lots of plain ol brass before that. My gun dates to the 1950s and we had never heard of +P back then.

 

[long40shot]

Sounds like I'll be fine using standard Bob brass. But, if i were to try the +P brass I'd need to back my load of a bit. Thank you guys.

Matt

 

[Ozzyblu]

+P or regular brass works. However, I finally bought Nosler brass and properly case formed to the AI. Previously I just shot factory loads to form brass. This worked but case separation was an issue. My suggestion is whatever brass you use, make sure you case form correctly.

 

[long40shot]

+P or regular brass works. However, I finally bought Nosler brass and properly case formed to the AI. Previously I just shot factory loads to form brass. This worked but case separation was an issue. My suggestion is whatever brass you use, make sure you case form correctly.

I've done a bit of reading on the subject. But just for the sake of conversation, could you explain what you mean by correctly forming cases?

 

[Ozzyblu]

Jam the bullets when case forming. What I read is you want the shoulder to move not the case body which could stretch and weaken the web. I am not an expert just what I found after having some case separation.

 

[long40shot]

Do any other manufacturers offer bob brass besides Remington and Winchester?

 

[JSH]

Matt, rather than jam into the lands, make a false shoulder. Use your 6.5CM die to neck up , then your 257 to size back down till you get a snug fit.

 

[Boyd L.]

Do any other manufacturers offer bob brass besides Remington and Winchester?

I’ve been following the thread curious if any new info would pop up about brass availability.
The aforementioned Nosler is the only readily available .257 Roberts brass I could find when I was on a search a couple years back. Winchester was my brand of choice and unicorn dropping’s were easier to find. I even conceded to using Remington but even it was unavailable through my usual sources. I finally bought a couple boxes of Hornady .275 Rigby brass, necked it down and formed cases. Full disclosure: my LGS found a bag of Remington .257 brass and asked if I wanted it. I forced all my prejudices out of my mind and forked over $44 for the 100 count bag. Jamming 120 grain Speers over a Roberts medium weight load of 4064 gave me inconsistently formed cases with a ring visible around the case at approximately mid-point of the case. Buy Winchester if you can get it, try the Nosler if you don’t mind the price, or neck down 7x57 of your choice. I hear Prvi Partizan 7x57 brass is an over looked option for forming cases. Frankly if I get in the bind obtaining brass again I’ll see if I can score some Winchester 6mm Rem brass to neck up.

 

[Tenderfoot]

Thought I would add a few cents worth here, first time I have joined in, I'm not a expert on anything however the 257 AI is my go to cartridge and has been for nearly 35 years,
I've owned or done extensive load work for 14 different rifles 15 if I count the rifle I rebarreled after having shot out the first barrel,
The rifles ranged from a rebored ruger number 1 from a 223 a rebored Browning safari grade in 243 win on a sako action, 98 mausers, a ruger 77, rem 700's and model 7,
All but four wore 22 inch barrels, two were cut at 26in and two at 21in.
I've formed brass from all manufacturers that wore a Roberts head stamp as well 6 and 7MM brass,
Jamming bullets help when forming brass but if the rifle is headspaced correctly it s not really necessary,
The 257 go guage becomes a no-go, use a virgin factory case for the go guage.
Also I found that a full case of slow burning powder produces a better fired case than the faster burning powders that leave air space in the case,
even though the faster burning powders are running at higher pressures i found that about 20% of the rounds required a second firing, with about 20% of The those suffering a split at the shoulder.
The slow powders only suffered about a 2% failure rate of producing a perfect case,
The powders i used most often as I bought in bulk at a reduced price were AA8600 and H5010