7mm RUM w/ factory tube and the 175 SMK?

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by Andy W, Sep 22, 2006.

  1. Andy W

    Andy W Well-Known Member

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    Have any of you 7mm RUM owners tried this bullet out of your factory 9.5 twist barrel? Sierra suggests a 8.5 twist or faster with this bullet, but I figured with the extra "push" that 90+ grains of powder gives it, the 9.5 should stabilize this bullet? anyone try this bullet?
     
  2. redstater

    redstater Active Member

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    bump
     

  3. coupalr

    coupalr Well-Known Member

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    Should be fine. I have been shooting 175 SMKs and 180 bergers out of my 1-9 twist 7mmSTW. It does have a 30" barrel so our velocities should be very close.
     
  4. älg

    älg Well-Known Member

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    Not directly related but I´ve used the 162 amax in a 7 rm with a 9 1/2 twist; hornady recommended 8 but they shot very well.

    With the speed you´ll get from the 7 rum you should be ok. I would buy a box and give them a try.
     
  5. Wild_Bill

    Wild_Bill Well-Known Member

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    Hi i have a Rem Model7 in 7mm SAUM and it has the same twist i have no trouble stabalising the 175gr Sierra, 180gr Berger or the 162gr A Max. in your barrel you will have no issue either. I also shoot a 284 Win for long range target shooting and it has a 9 twist and will stabalise all the above projectiles aswell.

    Go for it you will love the results.

    Cheers Bill
    Australia
     
  6. chris matthews

    chris matthews Well-Known Member

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    I shoot the 175s out of a 1-9 twist in a 7-08. With 7 RUM velocities a 10 twist will stabilize the 175.
     
  7. Andy W

    Andy W Well-Known Member

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    A range report for you guys;
    I loaded the 175 SMK with 3 different powders- Retumbo, RL25 and Thought I would try some RL22 as well. Trying to find load data for the 7 RUM was a little difficult, but managed to get a few starting loads with the above Powders. As a side-note I talked to Dave Brown @ Sierra and he said that Sierra was not planning to publish any data for the 7RUM, but he did give me some starting data. First working up with RL 25 I got mediocre accuracy with my starting load (the best accuracy with this ladder) but the velocity did not get over 2800 fps. With the Retumbo I got pressure signs right out of the hop @ 2850 fps. and with the RL22 I got about the same in the accuracy department as the RL25 and was getting pressure signs once I hit 2950 fps. I originally bought this gun for the action (I am a lefty and hard to find leftys in canada) But decided to see if this gun would shoot. Long story short I burn 25 grains more powder for what a 7mm Rem MAg will do. All of the negative I have heard and read about this caliber I experienced. Oh well I have a new barrel on order in .284 and probably going with the 7 mag.
     
  8. speedbump

    speedbump Well-Known Member

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    Longdraw, FWIW, although my 7mmRUM is a custom job (built before RUMs were in 7mm) it likes 5010 pulldown powder the best. Retumbo was so-so, the others a distant LAST! I haven't shot the 175 Sierras, but it goes like a house on fire with Cauterucio 176 & 156 VLDs. You might try some 5010 before you rebarrel - I chrono'd this combo at 3,300+ with a 30" Krieger.
     
  9. Ridge Runner

    Ridge Runner Well-Known Member

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    heck my 7mm STW runs 3330 fps or there abouts with wc872 behind a 160 nosler, not a hot weather powder but it works fine otherwise. H-1000 should also give him more velocity in the 7 RUM.
    JS
     
  10. James H

    James H Well-Known Member

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    I would try US869 and 50BMG before giving up.
    Load data here
    http://www.hodgdon.com/data/rifle/7mmremulmag.php
    Note loading data was with a 24" barrel so the slower powders should do better with a longer barrel. Data is not for SMK but will give you an idea of where to start.

    If you do decide to rebarrel you may consider the 7mm STW. You will get more performance than the 7mm Rem Mag. but at a cost. I have a couple Ruger No. 1s in 7 mag and one in 7mm STW. The 7mm Rem Mags are a pleasure to shoot but the STWs sharp quick recoil is definately unpleasant at the bench without a brake.
     
  11. Andy W

    Andy W Well-Known Member

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    Guys,

    I think I have decided on the 7RM because I don't want to have to put a brake on it. I have owned one in the past and I regret getting rid of it. I am planning to try the 175 & 168 SMK and the 162 Amax out of it. I have a Lilja barrel that I should be taking delivery of within the next week or so. My smith has a reamer for the 7 stw as well, but looking over alot of data it is a safe bet that with the same bullet weights the stw would be a 200 fps increase in velocity, maybe 300 if I got lucky. I rangefind/dial my scopes so what is a few more clicks? Plus I won't get the punishment of the recoil.