300 WBY brass for 7mm STW

Discussion in '7mm STW' started by briar rabbit, Feb 8, 2014.

  1. briar rabbit

    briar rabbit Well-Known Member

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    I have a 7mm STW that I have purchased but not received yet. The gentleman that I am buying it from informed me that he had 3-4 boxes of reloads that came with the purchase. He explained to me that when he had the gun built there was no brass in production and he stated out using the 8mm Remington brass but he has not happy with it. He switched to 300 WBY brass that he ran through a RCBS 7mm STW full length die once and it was good to go. Can anyone verify if it is that simple to convert WBY brass as I have a fair amount of it and will use it until I can get some Nosler brass from Shooters Pro Shop.
     
  2. chad k

    chad k Member

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    Hope someone gives a positive opinion on this pretty soon, cause that would be cool!
     

  3. frequent misser

    frequent misser Well-Known Member

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    Well I have some norma 300 weatherby brass so I guinea pigged this deal for you. I ran a norma case thru stw fl die filled it with 72 gr of 7828 and seated a 162 amax and squeezed it off. That was a very mild load from the book. Out popped a nice norma stw case. It does measure .02 shorter than regular stw brass.
     
  4. frequent misser

    frequent misser Well-Known Member

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    I should add that using this process you are headspacing on nothing but the belt as there really is no shoulder after sizing so dont load it up hot. Probably dont need to tell you that but someone else reading this may benefit. Some guys make arguments against using shorter formed cases but I havent had problems. I have formed some 257 weatherby from 7 mag in a pinch and got along fine. I do prefer to anneal after forming.
     
  5. Lefty7mmstw

    Lefty7mmstw Well-Known Member

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    If you don't have shoulder contact I'd use a mild load with a long bullet and seat into the lands for hard contact to create something for the case to get held back on. The belt will headspace for you but you may get more case stretch just above the belt.
     
  6. frequent misser

    frequent misser Well-Known Member

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    +1
    I should have stated that. Thats why I went with a162.