Is there a difference between a 300wm action and a 300RUM action?

Discussion in 'Long Range Hunting & Shooting' started by pburton, May 3, 2015.


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  1. pburton

    pburton Well-Known Member LRH Team Member

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    I am sure that this has been covered as some point in this forum. But I cannot seem to find the info that I am looking for. I just purchased a brand new action. It is listed as an 300 RUM action. As far as I can tell the 300 win mag and 300 RUM have the same bolt face and are on a long action. Is there differences in the actions? Do they take the same box mag? When I purchased it I was thinking about building a RUM, but have changed my mind due to the cost of brass and the difficulty to find it. I am thinking that I am going to build a 7 STW instead. I have this thing for 7mm. Thanks in advance.
     
  2. EdWalton

    EdWalton Well-Known Member

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    I'm not a gunsmith, but I've read the only difference is the follower in the magazine box.
     
  3. 445 supermag

    445 supermag Well-Known Member

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    Well if the 300 rum is difficult to find brass for, then you will be disappointed as the STW is almost impossible to find.

    Unless you go the 8mm mag and neck down I guess its fine. I just dont like that. OCD I guess.

    I have been wanting an STW also, but brass has stopped me for now.

    if I ever come across STW Brass then and only then I will build an STW.

    Best of luck
     
    Last edited: May 4, 2015
  4. pburton

    pburton Well-Known Member LRH Team Member

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    So after coming back and re reading my post I realized I screwed this post up. So I am trying to decide what to build. The 300 RUM was my first idea and the reason for buying the action. But since I have decided to consider some other options. One being the 7 STW and the other being a 300 win mag. That is the reason for the questions. Thank you for the responses so far. I think I read somewhere that they open the action up more because the size of the RUM case. I was trying to confirm this and to see if I could build a STW or a 300 win off this action. Sorry for any confusion. I think I spent to much time in the sun earlier today.
     
  5. jfseaman

    jfseaman Well-Known Member

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    300WM brass is available.

    RUM brass is hard to find.

    STW brass is unobtainium.

    If you want a 30 cal, I see nothing wring with a WM.

    If you want a 7 cal, I see nothing wrong with a 7RM or 7mm/300WM.

    Of course I would say...

    Think 28-Nosler or 308/28-Nosler (not to be confused with the not yet released 30-Nosler mess up)

    Sooooooo many chamberings, sooooo little time.
     
  6. fmajor

    fmajor Well-Known Member

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    OP - all these chamberings will fit in a Rem700 long action

    Now you just know that STW fans are gonna come and blast you for that as well as linking you to multiple sources for brass (that just as well may be "currently unavailable" :D

    300 Win mag - great chambering - HUGE array of components usually available everywhere (especially for the over-the-counter stuff).

    However, with the 300 RUM, well... as is often said, "there's no replacement for displacement" :D

    Much the same as for the 300 Win mag - 7mmRM components and over-the-counter ammo available nearly everywhere.

    The 7mm/300 Win Mag is a wildcat chambering, but is my "7mm" vote as it easily approaches 7mm STW performance with the added benefit of having reloading components (mainly brass) readily available.

    fixed that for you.....
     
  7. pburton

    pburton Well-Known Member LRH Team Member

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    Thank you for all the input. Its crazy how hard it is to pick a caliber to go with. 300wm seems like the best option for me at this point though. Brass and components are easy to find. It has plenty of energy out to 1000 yards for most North American animals. And I don't have one... Now to pick a good Smith to do the work. Any suggestions in this area would be helpful also since the last Smith I used to build a rifle I was not pleased with.
     
  8. 4xforfun

    4xforfun Well-Known Member

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    Looks like there is some 300 WBY brass around...how about a 7mm- 300WBY. Just neck down and shoot.....no FF process. balistic twin to an STW.
     
  9. jfseaman

    jfseaman Well-Known Member

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    sprechen für sich selbst:)
     
  10. MudRunner2005

    MudRunner2005 Well-Known Member

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    The RUM action will have wider feed rails on the bottom of the action, and uses a different mag box and follower.

    I have a 7mm STW that was built off an old 7RUM CDL action.

    You can use a RUM action for a magnum caliber, but can't use a magnum action for a RUM, without having the feed rails opened up, and swapping the mag box and follower for the correct RUM parts.

    If you want to build a RUM caliber, it's easiest to buy a 700 BDL or CDL in a RUM caliber, then use those parts to build. But if all you want is a magnum caliber, then buy a magnum BDL or CDL action to start out with.
     
  11. pburton

    pburton Well-Known Member LRH Team Member

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    MudRunner,

    Thank you for that info. That is exactly what I thought and wanted to confirm. I already have the action and it is from a 300RUM. I have a box mag and follower from a 7RM which will work with a 300wm. I have been wanting to build a STW for several years. But am concerned with the lack of brass available. I guess I could buy some factory ammo and use the brass from that. Just an expensive way to collect brass.
     
  12. mrb1982

    mrb1982 Well-Known Member

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    If you are looking for a smith, there are pile of highly reputable ones here on this sight and others. Because of locality for myself, I am and Chad Dixon fan at LongRifles Inc. He does some fantastic work, and cost is all about what you want. He likes to talk on the phone vs email and whatnot. Give him a call and he will tell you anything you want to know. All I have had him do is put a brake on a rifle, but then he more or less gave me a small tour of his shop while I was there. Pretty cool guy, knows his stuff, and super fantastic work.
     
  13. MudRunner2005

    MudRunner2005 Well-Known Member

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    You can always find 8mm RemMag brass, and run it through a FL 7mm STW sizing die, and you instantly have 7mm STW brass. The only downside is that it won't have "7mm STW" stamped on the head, but if you're like me, it's not a big deal. Also, 8mm RemMag brass is usually cheaper than STW brass, and almost always readily available.

    Nosler Custom Reloading Brass 8mm Remington Mag Box of 25

    Nosler Custom Reloading Brass 7mm STW Box of 25
     
  14. fmajor

    fmajor Well-Known Member

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    nisam razumeo?!?