7X338 Norma 35 deg Improved

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by krlemas, Feb 18, 2010.

  1. krlemas

    krlemas Active Member

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    I just put this together with a 28" Brux barrel with 8.5-1 twist and have been to the range a few times and it looks very promising. Today I shot a .290 3 shot group(100 yds) with 168 SMK with 89 gr. of Retumbo at 3280 with little pressure signs.I wanted to be able to shoot the 162 Amax and since the case capacity is 4 gr. less H2o than the 7 Rum I was wondering if any of you 7 Rum owners might have some load information that might help me.

    Ken
    Clearwater Precision
    NRA Life Endowment Member
     
  2. blipelt

    blipelt Well-Known Member

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    Is retumbo the only powder you have tried? Have you tried any heavier pills like the 180 berger or 189 Bob C. bullets?


    Brent
     

  3. krlemas

    krlemas Active Member

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    No I haven't but I do have some of the 180 Berger's on the way I am not familiar with the 189 Bob C bullets could you give me more info. on them.
    Thank You for the reply
    Ken
     
  4. trueblue

    trueblue Well-Known Member

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    With the 180 Berger, quikload is telling me that 89gr Retumbo will get you 3150fps , loaded off the lands @ COAL of 3.60. That should be close to top pressure, but obviously work yourway up.
    If you are going to load on the lands , 84gr is going to be close to max.
    With the 168's 90-92 gr will get you close to max. Again work your way up to these loads, as this just based off of quikload, and not personal experience.
     
  5. krlemas

    krlemas Active Member

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    I think you are right on with the 168's because the 215 primers are getting flat but my experience with them is that are softer than the 250's I am at 89 now so I am guessing that about 91 will be about max.
    Thanks for the info. for the 180's I hope they shoot like the 168 SMK's are. How about the 162 Amax have you found them to like to be close or jump to the lands with a .625 bc I would like to get them to shoot consistently.Thank You
    Ken
     
  6. blipelt

    blipelt Well-Known Member

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    don't really know to much about them yet. they are a 189 vld style bullet. Did a search here and found them and decided to give them a try pm me a address and I could send you some of each with the contact info.



    Brent
     
    Last edited: Feb 21, 2010
  7. krlemas

    krlemas Active Member

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    Do they look similar to the Berger 180? I still have about 12# of H5010 and some H870 which I used in my 7 STW and 30/378 I want to try it with the 180 Bergers and it sounds like those 189's that you have would be good to try also.Today I am going to check the case capacity, H2o, with a bullet seated to base of neck, load some more an go back to the range tomorrow.

    Ken
     
  8. blipelt

    blipelt Well-Known Member

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    pretty much identical just a smidge longer. You know you are getting me excited for mine now.

    Brent
     
  9. trueblue

    trueblue Well-Known Member

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    krlemas,
    can't help you with the A-MAX, as I don't shoot them.
    Keep us informed on your results. I have a friend building a 284 JAZZ that is basically the same as the 7-338 NORMA. Just not sure what the shoulder angle is.
     
  10. blipelt

    blipelt Well-Known Member

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    30* if I remember correctly


    Brent
     
  11. Freebore

    Freebore Well-Known Member

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    Ken,
    I shoot an 7STW and have loaded the 162 A-Max's. It is a Weatherby factory chamber so it has a lot of 'Freebore'. I use H-1000 powder and run them @3150fps. These bullets are moly coated that I shoot.
    Have not used them on game in this caliber but have and do use the 105 A-max's in a 243AI and took my first 'goat this year with that particular rifle. took it 375 yards killed it right there, heart shot. Was hoping for 750 or better shot but there were just too many too tight with alot of Wy wind. And had been shot at for a couple weeks.
     
  12. trueblue

    trueblue Well-Known Member

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    Brent,
    thanks for the info.
     
  13. Forrest Ebert

    Forrest Ebert Well-Known Member

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    I shoot the Bob Cauterucio 189 grain VLD in my RUM and with 90.7 grains of IMR 7828 I have chronoed this at 3150. I also shoot the Berger 168 & 180 and qwith the 168 I have a load of 88.5 grns. of Retumbo that is just one ragged hole but haven't chronoed it yet and this is out of a 26" tube. I found that the 168 VLD Hunting Bergers shoot a little bit better than the 162 A-max. I hope this will help a little with your load buildup.

    gun)
     
  14. krlemas

    krlemas Active Member

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    Thank you for the information I was at the range on Monday for more testing found that going up to 90 gr. of Retumbo with the 168 SMK opened my groups so I think I will call 89 my maximum for the 168's. I have some 180 Bergers now that I plan on trying, what load are you using with them? My rifle likes the 168SMK's so I plan on ordering some Berger 168's and working with them. I did get the 162 Amax going 3404 with 91 gr. Retumbo but I am not satisfied with the grouping so I am going to back off and maybe try a different powder maybe H1000 or R-25.

    Ken