257 Roberts cases

Jimbeaux82

Handloader
Jan 6, 2011
381
81
Last week a very good friend of mine gifted me a beautiful Kimber 84 M in 257 Roberts along with several boxes of ammo. Most of the ammo (Federal, Hornady, Nosler) is listed as +P on the boxes and cases but 3 boxes of ammo (Rem and WW) are not listed as +P. In the Nosler reloading manual there is a note about using the +P data in modern rifles (check) and with thicker cases designed for +P pressure.

So my question is once I shoot the non +P ammo should I discard the cases (horror) or can I reload them as per the +P data without worry. Has anyone here done this without seeing problems?

Thanks

Jimbeaux
 

DrMike

Ballistician
Nov 8, 2006
35,473
2,256
What a thoughtful gift, Jim! I've reloaded ammunition that was +P and ammunition that wasn't listed by that particular designation. You will need to ensure that the load you work up is not excessive by working up the first bit. However, you should have no problem whatsoever. The pressure level is still well below the maximum for brass.
 

Bruce Mc

Handloader
Oct 26, 2005
1,051
105
I've been loading for the Bob for over 40 years. I've found no difference in the actual case dimensions between the ones marked +P and those that aren't. Can't say about cases made before 1982. I loaded to a higher pressure since the first handload til today. Your Kimber should handle any +P load plus some more. Winchester and Remington introduced +P loadings for the Bob when they brought it back in the early 80s. Winchester put +P on theirs and Remington did not. +P warnings are for the old pump and converted Japanese rifles that were common when the Bob was a hit.
 

D21ALASKA

Beginner
Oct 29, 2013
208
108
Keep you're eye out on SPS as well for brass Jimbeaux. I noticed the other day that they had some 2nds on loaded ammo for the Bob as well as some 25cal bullets so they may have some more components at some point. I lucked into 100pcs of brass for mine this summer I think it was just randomly off there.
 

PJGunner

Handloader
Dec 11, 2010
1,857
459
There were quite a few lightweight sporters based on 93 and 95 Mausers so factories and SAAMI decided to keep pressures on the low side in deference to those rifles. Personally, I don't believe they're all that weak. They don't handle escaping gas as well as the later 98 Mauser but other than that I don't think they're as weak as made out to be. Just my personal opinion. Also, factory Plus P .257 Robt. are not all that much hotter than standard based on chronographed data of standard and plus P ammo shot in my Winchester m70 Featherweight. If I picked up a light sporter based on a 93/95 Mauser in .257R I would have no qualms whatever shooting either type ammo in that rifle.
Paul B.
 

truck driver

Ammo Smith
Mar 11, 2013
6,965
329
Jim I have been loading 257 Roberts 44 years and have had know problem with any cases I have bought either +p or other wise.
The older custom rifles were built on soft Mauser actions that couldn't with stand pressure over 58K so that's the reason for the +p marking on modern factory loads as a warning not to use in the older custom rifles unless the actions were heat treated.
 

Bruce Mc

Handloader
Oct 26, 2005
1,051
105
They show 110 gr AccuBond bullets in stock but when you try to order they show out of stock.

However, I do have a couple boxes of 110 AB loaded ammo ordered.
Typical these days, they can't keep up with the rapid sales when they actually have something in stock.
 

ShadeTree

Handloader
Mar 6, 2017
2,913
1,610
257 Roberts cases is something I don't have a lot of. Like you I've wondered about the + P rating. I've got a lot of 6mm cases, I was thinking I'd maybe run some thru the Roberts die, then fire form them. That would definitely give me +P rated cases as the 6mm is rated at 65,000 PSI. Be easy enough to do based on the cartridge drawings.
 

Scrumbag

Beginner
Feb 22, 2021
129
40
I never noticed any difference in the cases and I have 4 kinds I have done for volume after firing...
 

Scrumbag

Beginner
Feb 22, 2021
129
40
For good loads in the 257 Roberts, I really like the 120gr Speer SPBT. Just flat out shoots and great terminal performance.

Scrummy
 

JD338

Range Officer
Staff member
Nov 4, 2004
22,132
1,825
Jim,
Congratulations on the 257 Roberts. Is it a short long action? I've got a 700 Classic on a long action so I can seat bullets to a longer OAL which increases case capacity. My go to bullet is the 115 gr BT with RL22 for some impressive velocity that is essentially 25-06 performance. The case life with R-P brass is very good. I switched to Nosler brass and have no issues.
This rifle and load has proven itself on WT deer, coyotes, woodchucks, crows and the 600 yard gong,
You will enjoy the 257 Roberts, it's a great round that is underestimated.

JD338
 
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