Magnum action vs. Standard Long Action Differences

Discussion in 'Gunsmithing' started by arthurj, Nov 22, 2010.

  1. arthurj

    arthurj Well-Known Member

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    Other than the bolt face size, are there any differences between a Rem 700 magnum action and the standard long action? I have heard that an action for a RUM may have wider feed rails but is that the exception? For most actions, are the feed rails the same size for mag and non mag actions?
    Thank you
     
  2. J E Custom

    J E Custom Well-Known Member

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    The actions are the same Except for the bolt face and the extractor.

    The feed rails are different from a standard bolt face action to a magnum action in order to
    function properly.

    If you go from a standard bolt face action to a magnum bolt face action the rails are easy
    to open up but if you go the other way it is best to go to a center feed mag box and not
    fight the rails.

    J E CUSTOM
     

  3. arthurj

    arthurj Well-Known Member

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    JE,
    Thank you that is exactly what I was wondering. Is a center feed system just a mag box that pretty much replaces the standard mag box? So could this be worked into an ADL configuration?

    Thank you for your help,
    Al
     
    Last edited: Nov 23, 2010
  4. J E Custom

    J E Custom Well-Known Member

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    Yes it can be converted with a flat top follower and a different mag box.

    The center feed box is closed in at the top just enough to hold the round and does not use
    the rails and it can be adjusted to improve feeding simply by bending the ears in or out.

    If you know someone that has a 378,416 or 460 Weatherby Mark 5 you can look at the center
    feed on them and see how it works.

    I use this mag box on all of the Lapua cartriges and it works flawlessly.

    J E CUSTOM
     
  5. Radhimself

    Radhimself Active Member

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    So, if i wanted to take my 7mm sendaro and have it rebarreled to .338 RUM or .300 RUM

    Is it straight foreward rebarrel?

    What am i looking at as far as smithing is concerned?
     
  6. shortgrass

    shortgrass Well-Known Member

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    7mm Sendero, as in 7mm Rem. Mag.? Go from that to a RUM and the rails will need to be 'opened'. You'll need a UM mag box, too. And some patients...
     
  7. Edd

    Edd Well-Known Member

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    I have a BAT action that I thought was made for a 300 Winchester Mag. I am using a RUM case and a Wyatt center feed box. The cartridges feed from that box but there is very little clearance. I haven't tried but I don't think they would feed from a standard Remington box. Is there a published measurement on feed rails? I would like to measure mine to determine exactly what they are.
     
  8. IdahoCTD

    IdahoCTD Well-Known Member

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    The gap between the feed rails in the back of a Remington ultra mag action is about .567". I'd have to measure the front again but it seems like it was .080 to .100" wider at the front. I just went .014" wider at the front and the back on both sides. A standard magnum is around .540". I just opened a standard (originally a .243) short action to feed a 6.5saum with a Wyatt box so the numbers are still somewhat fresh. The feed ramp needed quite a bit of work to feed the fat little saum cases correctly too. I have run standard magnum cases in ultra mag actions for years without issues but a ultra mag case won't even fit between the feed rails of a standard magnum action. The ultra mags are .550 at the base of the case and standard magnum feed rails are around .540".
     
  9. Edd

    Edd Well-Known Member

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    The gap between the feed rails on my BAT action is .560" on the rear section and .611" on the front part.

    I bought it from Brunos. There wasn't a cartridge specified in the description on their website. It was just described with a magnum bolt face. I assumed it was intended to be used with a 300 Win Mag sized cartridge.
     
  10. Radhimself

    Radhimself Active Member

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    ok, so some smithing is required... damnit, i had a choice of 300 rum or 7mm rem mag at the time of purchase... now im kicking myself because i love my 270WSM and dont have a heavy hitter.
     
  11. Hired Gun

    Hired Gun Well-Known Member

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    Why not sell it and buy one in 300 RUM? Probably swap for less than $300 difference.