7mm RM to 7mm-300 WM AI questions.

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by banjo318, Feb 24, 2014.

  1. banjo318

    banjo318 Well-Known Member

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    So, short series of questions

    I want to have my chamber cut to a 7mm- 300 WM AI.

    1: What kind of reamer is needed for this?

    2: Will barrel life be improved at all?

    3: What about just a straight 7mm- 300 WM? Would go STW, but brass is impossible to find, and would go Dakota, but the story is that same for that.

    Thanks!
     
  2. MudRunner2005

    MudRunner2005 Well-Known Member

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    Why would you go through all that money and work for maybe 100 fps? I'd just rebarrel and keep it a 7mm RemMag, especially if you have all the dies and brass for it.

    1) You will need a PTG 7mm-300 WM AI reamer

    2) Barrel life will decrease because you are overboring the cartridge even more than it already was. The .300WM case is slightly larger than the 7mmRM case.

    3) 7mm STW brass is everywhere if you know what to look for. You can find Nosler 8mm RemMag brass everywhere right now, and all you have to do is run it through a 7mm STW full-length sizing die to make 7mm STW brass. No trimming, no headache, no issues. Just size and load. and you have instant 7mm STW ammo.

    I recommend the jump from 7mm RM to 7mm STW. That's a much bigger jump than going to the 7-300 WM.

    If you really want to step it up, call Brad Stair in Utah, and have him build you a 7mm STW Tejas. You can shoot regular 7mm STW brass and ammo in it to fire-form your cases.
     
  3. Jud96

    Jud96 Well-Known Member

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    Why would you go through all that money and work for maybe 100 fps? I'd just rebarrel and keep it a 7mm RemMag, especially if you have all the dies and brass for it.

    1) You will need a PTG 7mm-300 WM AI reamer

    2) Barrel life will decrease because you are overboring the cartridge even more than it already was. The .300WM case is slightly larger than the 7mmRM case.

    3) 7mm STW brass is everywhere if you know what to look for. You can find Nosler 8mm RemMag brass everywhere right now, and all you have to do is run it through a 7mm STW full-length sizing die to make 7mm STW brass. No trimming, no headache, no issues. Just size and load. and you have instant 7mm STW ammo.

    I recommend the jump from 7mm RM to 7mm STW. That's a much bigger jump than going to the 7-300 WM.

    If you really want to step it up, call Brad Stair in Utah, and have him build you a 7mm STW Tejas. You can shoot regular 7mm STW brass and ammo in it to fire-form your cases

    +1 the 7mm-300 Winchester doesn't have much over the old and proven 7mmRM.
     
    Last edited: Feb 24, 2014
  4. banjo318

    banjo318 Well-Known Member

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    Yeah, i guess you guys are right. Maybe ill just rebarrel to 338 rum or something like that. (Not lapua, brass is WAY to spendy)
     
  5. Jud96

    Jud96 Well-Known Member

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    You skipped the big .30s!
     
  6. banjo318

    banjo318 Well-Known Member

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    Is there a cartrige im missing thats so spectacular in the .30 other than the Winny, WSM, RSAUM, and RUM? Theres the weatherby, but, im pretty sure brass is hard to find on those suckers. Or is it that the brass is really expensive? I dont run any weatherby cartriges :p
     
  7. MudRunner2005

    MudRunner2005 Well-Known Member

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    Yes...The .300 Ackley Magnum. Hard to find dies and a reamer for, but it's one big nasty mother.

    7mm STW w/ 180 Berger VLD (left) and .300 Ackley w/ 230 Berger Hybrid (right)

    [​IMG]
     
  8. bigngreen

    bigngreen Well-Known Member

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    Skip the AI and just go with the straight 7mm-300 Win, you can just use regular dies and not have a custom die made.
    You'd need a reamer or a smith with the reamer, barrel life will not improve over the 7mag but be better than a 7 STW.
    This makes for an easy gain in performance over the 7 Mag with the 180 Berger, it's got a good balance to it and performs very well.

    I would also look a the pain old 300 Win mag, if it's built correctly and loaded with the 215 Berger it's very, very capable and you can roll in any were and get factory ammo if needed which may not matter.

    A 338 RUM does very nice but you've crossed the point were you'll want some weight in it and serious recoil reduction, makes a good long range prone shooter but does not work as easily as an all round rig as does the 7mm-300 Win or 300 Mag and if your worried about cost the big bullets and powder capacity costs!!