8mm brass 7mm stw

Discussion in 'Reloading' started by etisll40, Feb 29, 2012.

  1. etisll40

    etisll40 Well-Known Member

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    Has anyone necked down 8mm brass (Who's) to 7mm STW? Does it have longer case life? Is it a better case than rem 7mm stw cases. I think 7.92x57 is 8 mm right.

    Thanks
     
  2. Dano1

    Dano1 Well-Known Member

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    nope,

    7.92x57 is the 8mm Mauser case. You're looking for the 8mm Remington Magnum Case.

    I have not necked down 8mm Mag cases for my 7STW yet, but I would if I could find 8mm Rem mag cases. You'd also need a forming die as a .323" necked down to a .284" is quite a step. You'd probablly mess up the necks pretty badly. You need a intermediate sized die like a .308 or something to make it easier and neck it in stages. They do make them, however they are pricey.

    Dan
     

  3. etisll40

    etisll40 Well-Known Member

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    Thanks,

    I'll do some more research.
     
  4. 7stw

    7stw Well-Known Member

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    I have resized 8 mm Remington mag brass on several occasions, with good success. You must however, make sure your resizing die is bottomed out, and you must use lots of lube inside the neck. It will get you through in a pinch. Once in a while, you will split a neck. I have done this in the past, it works. The 8mm mag is the original parent case, as it is Layne Simpsons brainchild. Maybe someone will make some affordable brass that is decent. I have about 200 pieces of unfired brass now. Some of it is premium factory ammo. I bought it cheap from a guy who did not load, and sold his gun. I would have bought that to if I knew he was selling it. The last batch that I resized, shot well, and I got several firings from it. I neck size every other firing. Hope this helps.
    AIM SMALL, MISS SMALL. lightbulbgun) 7 STW.
     
  5. Varmint Hunter

    Varmint Hunter Well-Known Member

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    In the early years the only way to get 7STW brass was to neck down 8mm Rem mag brass. I've done at least a thousand cases by simply running 8mm mag cases into a 7STW FL sizing die and had no problems. I preferred the 8 mag cases even after 7STW cases became available because necking down cases usually results in slightly thicker necks which can then be turned down for maximum uniformity.
     
  6. etisll40

    etisll40 Well-Known Member

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    The comments here are really helpful, I really like my stw it is a truly great cartridge, power speed bullet selection, it's hard to get so much out of one rifle but the 7mm stw is a great catridge, so in my reloading, I want to be able to learn how to have a ready supply. It would be great if Lapua would adopt it. They seem to know the right metal mix for brass longevity.

    Would annealing the 8mm rem mag brass be helpful?
     
  7. lloydsmale

    lloydsmale Well-Known Member

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    i just did a 100 yesterday. Nothing but standard rcbs 7stw sizing die and hornady oneshot sprayed on the cases like any other time i size. Never had a single one get ruined. Loaded up 50 of them and the bullets seated just like in factory 7stw cases ive got so id bet the necks arent even in need of trimming. All rounds ran though the gun perfectly too.
     
  8. RT2506

    RT2506 Well-Known Member

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    Like has already been said back when the 7STW first came out it was a wild cat and the only way to get cases was to make them from 8mm Mag cases. Screw the FL size die down tight to the shell holder back off the ram and turn the die down another 1/4 turn to take all the slack out of the press. I also used Hornady 1 shot spray lube (give the die a shot up in it and spray done the cases making sure you get some inside the neck AND LET IT DRY FOR ABOUT 5 MINUTES). Do your sizing with one swift thrust and they come out perfect.
     
  9. Shumba

    Shumba Well-Known Member

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    I don't know if this will work but it might be worth investigating. I have a 300 Jarrett. I used to make 300 jarrett brass from necked up STW brass when 8mm rem brass was not available.

    Kenny Jarrett now sells 300 Jarrett brass made by Norma. A quick look at case dimensions shoul clear up if you could neck the 300 jarrett Norma brass down to 7STW and work shoulder and taper wise. If so the brass would be about. Good as you could get for the STW. Some Norma brass may be a little soft but I have not fiend this with the 300 Jarrett brass. I run the Jarrett pretty hard and the primer pockets are holding like new after 3 loadings.

    Possibly another option
     
  10. gamehawker

    gamehawker Well-Known Member

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    I see that this will work with RCBS dies but will this work with Redding Dies too?

    Got tired of waiting to see when anyone will get 7mm STW brass so today on Gunbroker I bid and won 2 bags of 50 8mm Remington Magnum brass.
     
  11. gamehawker

    gamehawker Well-Known Member

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    I just talked directly to Redding and the technician said it would be no problem resizing the 8mm Rem Mag to the 7 mm STW in their 7mm STW FL die. The technician suggested using Imperial Case Sizing Wax. He also said if I use Hornady One Shot more than likely they would get stuck.

    After the brass gets resized they may have to be trimmed.
     
  12. etisll40

    etisll40 Well-Known Member

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    Good to know, I like Redding dies.

    Let me know how it goes. What kind of press do you use?

    Ed
     
  13. gamehawker

    gamehawker Well-Known Member

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    RCBS Rock Chucker
     
  14. lloydsmale

    lloydsmale Well-Known Member

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    im not a fan of one shot for most heavy duty work but just neck sizing down some brass isnt hard to do. One shot worked just fine when I did it. If you want the best lube for sizing at the best price go to your pharmaisist and ask him for anhydrous lanolin. Make sure its anhydrous though. You can but a 2 lb tube of of for less then the cost of a tin of imperial sizing wax and its the same thing. Lanolin is also the main ingreditiant in lee and dillon lubes. I also use it to make cast bullet lube. A tub of it will last the average handloader two lifetimes. Ive found NOTHING better for case sizing.