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.300 win. mag. brass into .257 wby. mag. brass

kallie
Can .300 win. mag. brass be resized to make .257 wby mag brass? I know the shoulder dimensions are different, as well as the length. I am also assuming the necks would have to be turned. Thanks for your input.
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Comments

9 comments

Date Votes
  • MIKE WISKEY
    YES BUT...............A LOT MORE WORK THAT IT'S WORTH IMO
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  • kallie
    Thanks Mike, But what does IMO mean.
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  • nononsense
    kallie,

    It's an acronym or initialism used frequently on the internet. There are entire lists of these available by search.

    IMO = In My Opinion

    IMHO = In My Humble Opinion

    LOL = Laughing Out Loud

    Best.
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  • sandwarrior
    quote:Originally posted by nononsense
    kallie,

    It's an acronym or initialism used frequently on the internet. There are entire lists of these available by search.

    IMO = In My Opinion

    IMHO = In My Humble Opinion

    LOL = Laughing Out Loud

    Best.



    That might mean this is going to be a lot more project than you think. In spite of the fact Weatherby .257 Brass is $2.00 ea., it is still way easier to pay that and reload than it is to form readily available .300 Win Mag.
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  • kallie
    Thanks for the lesson in "Internet Talk". I have a couple of hundred .300 cases, so I thought I might give it a try. I just wanted to see if anyone else had already given it a go. I had a T/C Contender in .30 Herrett years ago. That case is made by shortening a .30-30 case and fire-forming to blow the shoulder out. Thanks again for your thoughts.
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  • nononsense
    kallie,

    None of my examples of acronyms were pointed in any way, just examples.

    Here is a list of some of the common acronyms:

    http://www.magicpub.com/netprimer/acronyms.html

    Since you've had some experience with case conversions, I'll just hit the high points which might be a little repetitive for you but clear:

    Cast your .257 Weatherby chamber. This gives you a standard to measure from and compare to the conversions as you work on them. It is important since the .300 Win. Mag. cases are longer at the start.

    Make sure your dies are clean.

    Anneal the neck and shoulder of the .300 Win. Mag. cases if they have been fired. This will make them easier to shape.

    Use Imperial Sizing Wax when you start the process. A little goes a very long way, believe me.

    You might consider using a Hornady Neck die in an intermediate diameter to avoid collapsing the case necks. Try a couple first before ordering a new die.

    Headspace is controlled by the belt obviously so this allows you to push the shoulder of the .300 Win. Mag cases back a tiny bit to allow for fireforming in the chamber.

    It's not a project I would bother with but I won't try to dissuade you because I've been a willing participant in some incredibly labor intensive wildcat conversions in the past.

    Good Luck and let us know how it turns out!

    Best.
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  • kallie
    Thanks for the info. I am truely thankful for the acronym info. It's never too late to learn something new. I will give your suggestions a try, and let you know what I find. Thanks.
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  • sandwarrior
    kallie,

    I do apologize as it was me who saw the potential humor in nononsenses post. He is, for the vast majority of the time, an even keeled poster with plenty of knowledge. I can tell you his post wasn't meant as a jab. My intent was more to laugh at the situation and not at you.

    The reason I say this is because I attempted to neck down some .300 WM cases to .257 Wby. I did use my 7 WSM dies just to intermediate size down the necks. Then I trimmed it and then ran it through my .257 WBY die. I was using RCBS dies and lube for the whole process, not Imperial Sizing Wax which may have made a difference. Then I had to turn down the necks as they got too thick. Fire-forming was last on the list. Another huge frustration I had was I had a long barrel. And in the process of fire-forming I was getting terrible accuracy. Turns out too much friction and velocity were tearing up my lighter bullets. Noslers worked. Bergers, Hornadys, Wildcats and Sierra's didn't. they came out okay eventually, but it was a lot of work. A lot of work that you just like to have to do.

    One day I found 100 cases for sale here on GB and I bid on them and got them for $.50 apiece. That was much easier. then I found another deal from either Graf's or Wideners and I got 100 of them also. Anyhow, that's why I suggested finding the brass. Bumping back from an angular shoulder to the radiused shoulder in five calibers down proved to be something I wasn't really into doing. But it is doable if that's the only way you're going to get brass.
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  • kallie
    Thanks Sandwarrior, It sounds like alot of work, for minimal gain. I will just list my .300 brass on GB, and use the funds to find .257 brass. All of you have been a great help. Thanks for your input, and until next time, good bye.
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