Rechambering .300 Weatherby to .300 RUM

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by 30 Caliber Mag Fan, Jan 25, 2005.

  1. 30 Caliber Mag Fan

    30 Caliber Mag Fan Member

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    I have a rifle that I am strongly considering rechambering to .300 RUM from .300 Weatherby. It seems intuitive to me that it would be a really easy rechamber job save and accept for cleaning up the freebore. Any comments or suggestions? I know that I will need to change out magazine box and alter feed rails?

    I just think that the .300 RUM is a better long range hunting round than the .300 Weatherby. What are your thoughts?

    Thanks in advance.
     
  2. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    30 Cal Mag Fan,

    Converting a standard belted magnum chambered rifle to a RUM is a relatively simply task. Hell I built a 338 RUM out of a Rem 700 chambered for a 270 Win thsi summer and it was easier then most would think.

    I assume your rifle is a Wby MkV?

    The 300 RUM will give you at least 100 fps more velocity then the 300 WBY even with the Wby rounds freebore. The nice thing is that with a properly set up throat, the RUM will offer accuracy that the Wby could not.

    Depending on your rifle, you would need to shorten the barrel by up to .400" to clean up the freebore. Once the rifle muzzle is recrowned you could be looking at close to .500" shorter barrel with this conversion.

    Other then that I do not see any other problems.

    Good Shooting!!!

    Kirby Allen(50)
     

  3. BountyHunter

    BountyHunter Writers Guild

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    Fifty driver

    "300 Rum will offer accuracy the 300 Weatherby will not". HORSE PUCKEY!!!

    At least if both are set up right, the weatherby will equal at least anything the RUM can do in accuracy if not beat it 90% of the time.

    300 Weatherby has been used in LR BR for years very successfully and set many records. Last one I had built shot a 10 shot, 5.9" and 100 score at 1000. Never seen a RUM do that anywhere.

    Put min SAAMI match chamber 300 Weatherby barrel on it and it will do anything is needed.

    Absolutely no comparison in quality of brass of Rem vs Norma and 100 fps is nothing. You do not have to sort through 200 rem cases to get 40 shootable ones.

    BH
     
  4. 30 Caliber Mag Fan

    30 Caliber Mag Fan Member

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    My .300 Weatherby is a custom rig using a Model 70 Classic Stainless with a Lilja barrel. And I believe that it does have a minimum SAAMI match chamber.

    Wow, I did not think I would be loosing .50 inches of barrel. Really?
     
  5. 5Redman8

    5Redman8 Well-Known Member

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    BH...most Weatherby's are set up with freebore...not good for accuracy. I think this is what 50driver is referring to in accuracy. Also speaking to just this situation, the RUM will be more accurate because it would be set up right.

    30cal..... .50inches is just a HALF inch!!!

    Kyle
     
  6. Mike375

    Mike375 Active Member

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    I have had a lot of Weatherbys both factory and set up on bench guns. I also have considerable money tied up in Wby custom shop rifles with more about to be ordered. In other words, I am not anti Wby /ubbthreads/images/graemlins/grin.gif

    There is no doubt that a Wby that has a freebore dimater that is just about on bullet dimater will shoot and you would make a serious mistake to bet against one.

    HOWEVER, in my experience they have two disdvantages over a conventional chamber. The first one is that accuracy is more dependent on consistent neck tension and you can neck turn till thee cows come home but brass varies over time with use.

    Secondly, I think conventional chamber (all else equal) shoots better with more loads and that couldbe important if you are trying to get your good load with a specific bullet.

    On a plus side for the Wby chamber (my experience only) I think they are more likely to put a shot from a clean cold barrel into the group, or from a warm barrel or from a barrel that is cold with hard fouling in it. They also suffere less from pressure soikes with varying barrel conditions. But all of that is more hunting rifle related than target shooting.

    Mike
     
  7. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    BountyHunter,

    My reference was comparing a tight, short throated 300 RUM chamber to a factory spec 300 WBY chamber with the usual freebore.

    When both are set up in equally quality chambers I agree they both would shoot lights out at any range. I would still not say the 300 WBY will consistantly out shoot a RUM with equal quality rifles and ammo quality, but I would say they would be a draw in accuracy level.

    Again, I was referring to a custom chamber to a factory spec chamber.

    Good SHooting!!

    Kirby Allen(50)
     
  8. 30 Caliber Mag Fan

    30 Caliber Mag Fan Member

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    Kyle-

    I was just worried about my barrel channel; I didn't want a gap that I could drive a truck through. Purely a esthetics issue; I suppose I could get over that.
     
  9. 5Redman8

    5Redman8 Well-Known Member

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    The set back would be minimal so the barrel channel gap should not increase significantly. Totally understand that looks are important!!!

    Kyle