Re-chamber 338 RUM to an Edge--Your thoughts

Discussion in 'Long Range Hunting & Shooting' started by philny1, Jan 1, 2008.

  1. philny1

    philny1 Well-Known Member

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    Going to rebarrel my 270 AM to a 338 Edge. Just don't have a use for it. Have a Hart barrel ordered for the project. Will finish at 30" including brake.
    I hunted this year with a Rem 700 LSS 338 RUM 26" factory barrel with some success. Love this round.
    I'm toying with the idea of re-chambering my RUM to an Edge. My reasoning is to try to avoid any posible confusion with the ammo. Both rifles will be going on some of my trips. Although I still plan on using the 225 gr Accubond in the LSS and the 300 gr Sierra in the new gun. Identifying the ammo should not pose a problem. Then there is the remote possibility both rifle may shoot the same load--wishful thinking!!
    I'm getting just over 3100 fps with the 225 gr Accubond using RL-22. This is my zero. Another load gives me a tad over 3200 fps w/ RL-25.
    Ballistically would I realize any gains to warrant the new chamber in a 26" barrel.
    Your thoughts will be appreciated. light bulb
    BTW; Any one with an interest in the 30" AM barrel, it has 400 rds through her make an offer.
     
    Last edited: Jan 3, 2008
  2. davewilson

    davewilson Well-Known Member

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    i have an edge and love the round. but to rechamber a 338rum, i don't think the gains you will receive will be worth it. first off when you rechamber a barrel, you'll loose a bit of barrel length. most smith's, maybe not all, but most will chop off the barrel threads and on a Remington, that's around .900 in length. so now you're down to a 25" barrel.if you want to shoot the 300 gr bullets, a 30" barrel is much more advantageous. generally speaking the advantage an edge has over the rum is about 100fps "AT BEST". Shawn is working on a new chambering technique that is showing a lot of promise, that could be another option. maybe he'll jump in here, you have a gunsmith and "Shawn's cartridge" type of question, nobody better to answer your question than he.
     

  3. Shawn Carlock

    Shawn Carlock Sponsor

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    Out of a 26" tube with light bullets rechambering is hardly worth doing from a performance standpoint. I do however agree with you on slipping the wrong ammo in the wrong rifle that would full on suck! Most of the time you can stretch the RUM chamber to an Edge with out chopping the shank. I would give some thought to doing it and if you do you could set up both rifles to accept both loads allowing you to switch ammo if you ever got in am ammo bind especially if you plan on taking both on the same trips. Again from a pure performance standpoint not really worth the effort.
     
  4. royinidaho

    royinidaho Writers Guild

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    I've been thinking of taking my REM 700 338 RUM to the local "hacker" and having him run a 300 RUM reamer in there, if its doable. If I can keep the full 26" length, the brake is already installed, I figure I'll gain a little velocity.

    Why do this? For fun, I guess. I will then have the same rifle grow from 338 WIn to 338 RUM to 338 Edge. From there when all of my other endeavors are completed it'll grow to something else.

    I'm kind of like gamehauler, "why do I do some of the dumb things that I do":rolleyes::rolleyes:
     
  5. Shawn Carlock

    Shawn Carlock Sponsor

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    Roy,

    You can't just run a 300 RUM reamer in and move the shoulder foreward. The neck, throat and leade must also move as well. If he has a 338 RUM reamer and wants to run it in the extra .094" or so that will work.
     
  6. royinidaho

    royinidaho Writers Guild

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    Thanks Shawn

    Another dumb idea down the tubes?

    What I know, I really know well. What I don't know really gets me in trouble sometimes but usually only once.:D:D
     
  7. philny1

    philny1 Well-Known Member

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    Just out of curiosity has anyone ever fired a 338 RUM in a rifle chambered for the Edge.
    No such thing as a dumb idea!! Usually at that point in time it all made perfect sense. But today it is a bit less than brilliant.
    Still on the fence--like the idea of two rifles chambered for the same cartridge.
     
    Last edited: Jan 4, 2008
  8. NYLES

    NYLES Well-Known Member

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    "Usually at that point in time it all made perfect sense."

    Would this be the same point in time he said "Watch This"?
     
  9. long ranger

    long ranger Well-Known Member

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    If it was fired in a controlled feed rifle action, the extractor may hold the casing strong enough for the firing pin to fire the cartridge. Th chances of having gun all over your body would be high as the headspacing would be off by over .090" so would likely make for some outrageous chamber pressures.
    If fired in a push feed like a Rem 700 chances are the cartridge would not go off as the firing pin may not strike the primer hard enough as the cartridge would likely move forward away from the firing pin, due to the excess headspace.
    Keep in mind these rimless calibers headspace off the shoulder.
    I certainly would not recommend trying this.
     
  10. philny1

    philny1 Well-Known Member

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    I certainly don't plan on trying out a 338 Rum in my new rifle. Can't help but wonder about the out come if a round should mistakenly find it way into the chamber.
    I will be using a Rem 700 receiver, so maybe it won't fire.
    With the headspace off by .090" I don't understand how it would/could build excessive pressure. Of course I could write a couple books about what I don't know about these rifles.
    Please explain.
     
  11. long ranger

    long ranger Well-Known Member

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    Chances are with your 700, the ejector would keep the primer far enough forward to prevent the firing pin from doing its job.
    Headspace, is simply the tolerance assigned to a caliber, typically the dimensional difference between an unfired cartridge that is of spec and the chamber dimensions, that the reamer cuts, is about 3 thousanths of an inch.
    Having 90 thousanths of an inch will not "control " the "explosion" that occurs when a cartridge is fired.
    In a normal chamber when the cartridge is fired, the "explosion" ( proper terminology is, the rapid expansion of gasses caused by the burning of the confined propellent) is contained by the steel of the barrel and action, the control is produced by only allowing the cartridge to expand a few thousanths of an inch before the brass casing is confined by the tolerances of the action/barrel making the path of least resistance, the bore, the easiest way for the expanding gasses to travel, thereby pushing the bullet down the barrel.
    When you have too much tolerance, or too little for that matter, uncontrolled pressure spikes occur, so instead of the cartridge creating 50000 CUPs for example without the contol of the confined space of the chamber you can easily get double that, which normally results in a catestrophic failure, or FUBAR.
    Not sure if my expanation makes total sense, but hopefully you will get the idea.
    I build guns far better than I can explain them.
     
  12. philny1

    philny1 Well-Known Member

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    Thanks for your reply.
    I was thinking that case seperation would occur with .090 excessive headspace and you would get blow back rather that a pressure spike.

    BTW; I have an unopened box of 500 Sierra 300 gr MK, priced at $230.00 plus S&I.