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257 Roberts +P?

Discussion in 'Rifle Country' started by Jessesky, Nov 30, 2019.

  1. Jessesky

    Jessesky Member

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    I picked up my new 257 Roberts Mauser 98 from the FFL this past Friday. After I did the transfer, I looked over in the ammo grab bag. What a coincidence, it was loaded with 257 Roberts brass and ammo. I was able to buy all 82 pieces of brass and 38 loaded rounds for a measly $20. A Black Friday miracle!
    575AAAF1-933C-4ABF-8826-2A354A7B361B.jpeg
    I did notice some of the ammo was labeled +p. Anyone have experience loading to these levels or replicating the performance safely by handloading?
     
  2. mshootnit

    mshootnit Member

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    Is that a new production 98 or an older used one?
     
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  3. Archie

    Archie Member

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    The initial development of the .257 Roberts (.25 Bob, to friends) was necking down a 7x57mm Mauser case to .257 caliber. As the rifles suitable at the time were based on the 1891 Mauser action, the pressures were kept to the 7x57mm level. The "+p" designation is for that cartridge chambered in the '98 Mauser and 'modern' bolt guns suited for full pressure.

    As Mshootnit implies, older guns can be well used - or the metal aged - and not quite as secure as one would wish.
     
  4. ExAgoradzo

    ExAgoradzo Member

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    Someone on this forum once gave me the advice to the effect that you should always stay within the recommended pressures of a round. If you want ‘more’ than that you should move up rounds (in this case presumably to the .25-06 or to the queen of 1/4 bores: the .257WBY). I have stayed within the realm of this advice. Having said that, I am happy for you on the find. A Bob is on my list of rifles I would like to have.

    Greg
     
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  5. ExAgoradzo

    ExAgoradzo Member

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    I’d like to see a pic of the rifle!

    please.

    Greg
     
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  6. Jim Watson

    Jim Watson Member

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    Well, not exactly.
    The .25 Roberts wildcats (Neidner and G&H versions) were commonly built on Spanish Mausers. Probably also on German '98s and Springfields too, but the 91-96 small ring actions were the weak link.
    BUT, the .257 Remington Roberts commercial round was originally chambered in the Remington Model 30, a 1917 derivative that was probably the strongest action of the period. This would require that Remington was light loading to protect later customs and rechambered wildcat/proprietary .25s, not their own guns.
    The three cartridges are NOT interchangeable, no accidental or convenient off the shelf substitution possible.
    Are we to think that the case?

    Also note that the .257 Roberts +P for "strong modern actions" is at the same chamber pressure as the .30-06, and less than the .270 Win which considerably predates the .257.

    I don't know why the .257 is loaded so light, LESS than its parent 7mm Mauser, but the conventional wisdom does not stand up.
     
  7. tmd16556

    tmd16556 Member

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    That’s a great haul on the 257 brass! I managed to stumble on about a half of that brass for the same price and felt lucky. It seems impossible to find until it’s easy.
    I’ve been studying up on loading for the custom Springfield I have in 257 Roberts but haven’t gotten to loading it yet. I’ve read the +p brass is a bit thicker usually than the older stuff. There should be some variation in brass volume and pressure. I’ll have to test that vs some of my 1930s era brass. Unfortunately a lot of that brass has corrosion from bad powder sitting in a basement for 60 years, thus the envy over that brass haul.
     
  8. Jessesky

    Jessesky Member

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    It’s only a barreled action at the moment! Will take a bit of work but it has a lot of potential. I’m working on the stock now.
    757DA052-67B9-4F59-92CA-E0F708F32ED4.jpeg
     
  9. Jessesky

    Jessesky Member

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    It’s a VZ24. I was more curious as to what is +p and how I could replicate loads like the Hornady Superformance. I have no worries as to the strength of the rifle if loaded properly.
     
  10. rizbunk77

    rizbunk77 Member

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    My nosler manual lists no special word for 257 Roberts +P and shows a max load of 45.5 gr. IMR 4831 behind a 100 gr. Bullet Winchester case CCI 200 primer.
    My Hornady manual says that some cases are designed for +p pressures and may have reduced capacity, and that cases should be segregated by brand for load development.
    It also mentions that newer rifles such as the Ruger M77 , Rem. Classic 700 are appropriate for the +P pressure levels.
    It further states that all following listed data is for +P rifles and cases and should only be used in modern firearms designed for the cartridge. It lists 45.2gr. IMR 4831 as a max load for 100gr bullets and a starting load of 38.8gr . Hornady/frontier case, WLR primer. All max loads should be reduced for initial testing.
    So I take it to mean that the +P data is for new production commercial rifles known to be strong.
     
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  11. Jim Watson

    Jim Watson Member

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    I know what they SAY but if you look at the SAAMI specs, .257 +P is 50000 CUP, just the same as .30-06.
     
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  12. mljdeckard

    mljdeckard Member

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    My dad once traded ten boxes of .257 Roberts for a old trailer.

    So I inherited his when he died, it's a Remington 760. My sister took it first, and I had to explain to her, that she can't run +P ammo in it, because it's a pump with a turning bolt. I went to the shelf at Sportsman's Warehouse, and all they had was.....+P. So I bought her a Ruger American in .243 to trade, and took it back. I can handload for it to regular pressure.
     
  13. Jim Watson

    Jim Watson Member

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    Considering they made the 760 in 270 Win, such limitations live only in the imagination of corporate lawyers.
     
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  14. Swampman

    Swampman Old Fart

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    The tables below show 2013 SAAMI transducer pressures for the 6mm Remington, .257 Bob and .257 Bob +P (please ignore the 6x45mm data, it's only there because I was too lazy to edit it out).
    20191201_013828.jpg
    20191201_013925.jpg
    Note that all of the 3 above cartridges are based on the 1893 vintage 7x57 Mauser. The 6mm and +P Bob just have slightly thicker brass than the standard Bob.

    I fully understand and agree with keeping pressures down around the 50K mark if you're loading for an '89 through '96 Mauser, but limiting a well put together '98 or quality modern sporting rifle that much is a little silly.

    Here's a list of a few rifles that have been chambered in the 6mm Remington with it's 65,000 PSI.
    Would anyone argue that those (mostly flawed) semi autos and pumps have a stronger action than a good Mauser '98? Does anyone think they have better gas handling in the event of a ruptured case?

    A good '98 Mauser using .257 +P or resized and expanded 6mm Remington brass is capable of handling just as much pressure as a rifle chambered for 6mm Remington and will give slightly higher velocities at the same pressures.
     
  15. Jim Watson

    Jim Watson Member

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    Slamfire won't agree that there is such a thing as a "good" '98 Mauser.
    But when you get into the "modern" guns from Remington and Winchester, the concept applies.
    But the problem is, how do you know when you are there? There is no published pressure tested data for full power .257. Roberts shooters are hamstrung by the notions of 1934 or are dependent on rule of thumb or calculated loading.
     
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  16. js8588

    js8588 Member

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    Yeah, you could build a "magnum" off a VZ24 action. The Bob +p will be no issue.
     
  17. GooseGestapo

    GooseGestapo Member

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    Don’t get too caught up in the .257Robt +P whirlwind.
    I’ve been loading and shooting the “Bob” for 36yrs. Pre-dating the +P origins.

    FWIW, Hodgdons published NON-+P data exceeds the +P velocity parameters, (published factory +P ammo speeds), so loading the .257 to alledged +P pressures is a non issue.

    From my experience, the published Hodgdons maximums, are also “accuracy” loads in the 4 .257’s I’ve loaded for.
    Re: case volumn. This follows age. Older brass has greater volumes. Except for Norma, which has greatest volume. I mostly have/use Federal, as I was gifted 400pieces 30yrs ago, and still have some that are ofb.

    For the 115-120gr bullets, I prefer H and IMR4831. For the 100gr IMR4350 is most accurate, but H414 and H380 are no slouches and top 3,100fps from my 22” ERShaw barrel.

    Pick the bullet you need to meet your need, pick the powder from Hodgdons list that gives the best velocity, load some up and try them!

    The only powder I recommend staying far, far away from is Hybrid100V. Even the starting load cratered primers, burnished case heads, and gave stiff extraction. I’ve never experienced any of these with any other powder in the Roberts.
    I fed it to the azaleas...
    For 75-100gr try H380. 100gr, IMR or H4350, 110-120, H4831.
    Keep it simple!
     
  18. Jim Watson

    Jim Watson Member

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    I recall articles about the "Three Inch Roberts" being a Model 70 with '06 bolt stop and magazine follower so you could load spitzers out to the lands.
    The REAL enthusiasts reamed the throats to take even longer OAL.
     
  19. Slamfire

    Slamfire Member

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    World War 1 era and earlier M92's, M96's, M98's were built for cartridges in which the maximum pressures were 43,000 psia. By the time you get to WW2 the maximum pressure of the 8 X 57 mm is 46,000 psia. Maybe the metallurgy improved, but there were still millions of older GEW 98 rifles in inventory, many of which were converted to K98 configurations.

    These older actions were made out of plain carbon steels, and when you look at metallurgical analysis of period metals (I found a couple of metallurgical analyses of 19th century bridges), the same equivalent steel today is much cleaner, and stronger. That old stuff always has more slag and impurities which makes the steel weaker.

    Now, you put the 257 Roberts in a rifle made out of a modern 4140 alloy, such as my pre 64 M70 Winchester

    CLi5zBA.jpg

    oU2MWtx.jpg

    edUsFil.jpg


    than your safe pressure limits are the same as any other modern rifle action made out of modern alloy steels. This rifle also has a long throated chamber, so I was able to seat the bullet out about two tenths of inch further than factory. I think this is just great and, it allows me to pack more powder in the case. I have no idea what pressures I am running, but the thing feeds and extracts reliably.

    IqtaafW.jpg


    If you plan to use a vintage action understand the limitations of the things. The manufacturer did not anticipate or plan for you to be using that rifle long after the demise of the factory and after the funerals of all the people who made that rifle. You can rest assured that the manufacturer did not use a better grade of steel than needed, nor was the heat treatment altered, to make the surface harder, just in case some one wanted to use a 60 kpsia cartridge. These are things you can bet on. If you are going to use military actions for cartridges whose operating pressures are above the proof pressures of the original action, you need to be cautious. You should always wear your shooting glasses. You blow a case head, due to receiver seat set back, shooting glasses might save your eyeballs. No guarantee, but they might.

    I found this an interesting post on the M1917 action:

    Thoughts on my sporterized Springfield M1903?

    https://thefiringline.com/forums/showthread.php?p=6546703#post6546703

    I've experienced a catastrophic receiver failure. I will tell you flat out it's NOT something you EVER want to happen.


    Over 100 stitches in my face/neck, shattered jaw that was wired shut for 12 weeks, a hole in my neck to breath through, weeks of missed work, weeks of being fed through a straw, lost 20-25% of my body weight, permanent nerve and tissue damage resembling the effects of a light stroke.
    Hop right on that train Dude cause my seat is empty.



    One of the "glass hard" P17 actions re-barreled to a belted magnum. Those actions are some of the strongest known (sarcasm). Some of the "over treated" ones are really strong right up to the point when they grenade.


    You should always check to see if either the lugs or the receiver seats are deforming. If they are, take the receiver off the barrel and throw it into a trash can.

    You can do whatever you want with your action, but I think it is prudent not to use cartridges of higher pressure than for what the action was built and issued. The older you get, the more you realize, permanent injuries don't go away, and the human body does not have redundant parts. Pay $250,000 to $500,000 or so in medical costs, because some $300 antique blew up in your face, and you won't think that rifle was such a great deal.
     
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  20. rbernie
    • Contributing Member

    rbernie Contributing Member

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    The long magazine body and bolt throw of the Savage short-actions are great for handloaders that shoot the Bob; OAL of 3.0” are possible without any action / magazine modifications.
     
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  21. Jim Watson

    Jim Watson Member

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    I was worried about "cramming powder" into your 55 year old cone breech, but a 100 gr bullet + 45 gr H4350 is only Hodgdon maximum for 1934 Roberts 45400 CUP.

    I wonder how much if any the steel was improved from 1918 til the 1930s when Remington thought the design was adequate for .270.
     
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  22. Slamfire

    Slamfire Member

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    Don't know. The expensive book I purchased on sword metallurgy only goes to the 16 th century. I have found smatters of data here and there. Testing and collecting metallurgical data costs money. Who is going to pay for this? How would that data base make profit? Everyone has an itch, but is everyone given a free back scratcher?
     
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  23. mshootnit

    mshootnit Member

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    Ruger made some nice M77's in 257 Roberts. Still do actually
     
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  24. rbernie
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    rbernie Contributing Member

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    My understanding is that the adoption of the electric arc furnace in the 1920s allowed for process control in steel making that was not available prior to that. I was taught that metallurgy prior to, say, 1924 or so, was more luck and artistry than repeatable skill.
     
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